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81377247672 = 23337331162601
BaseRepresentation
bin100101111001001110…
…1100100000110111000
321210001022122111122000
41023302131210012320
52313130033411142
6101214552501000
75610414122640
oct1136235440670
9253038574560
1081377247672
113156a3756a6
12139310aa760
13789b578476
143d1da47520
1521b436c14c
hex12f27641b8

81377247672 has 128 divisors (see below), whose sum is σ = 259122547200. Its totient is φ = 23180256000.

The previous prime is 81377247671. The next prime is 81377247673. The reversal of 81377247672 is 27674277318.

81377247672 is a `hidden beast` number, since 8 + 1 + 37 + 72 + 476 + 72 = 666.

It is an interprime number because it is at equal distance from previous prime (81377247671) and next prime (81377247673).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81377247671) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 419172 + ... + 581772.

It is an arithmetic number, because the mean of its divisors is an integer number (2024394900).

Almost surely, 281377247672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81377247672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129561273600).

81377247672 is an abundant number, since it is smaller than the sum of its proper divisors (177745299528).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81377247672 is a wasteful number, since it uses less digits than its factorization.

81377247672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162954 (or 162944 counting only the distinct ones).

The product of its digits is 5531904, while the sum is 54.

The spelling of 81377247672 in words is "eighty-one billion, three hundred seventy-seven million, two hundred forty-seven thousand, six hundred seventy-two".

Divisors: 1 2 3 4 6 7 8 9 12 14 18 21 24 27 28 36 42 54 56 63 72 84 108 126 168 189 216 252 331 378 504 662 756 993 1324 1512 1986 2317 2648 2979 3972 4634 5958 6951 7944 8937 9268 11916 13902 17874 18536 20853 23832 27804 35748 41706 55608 62559 71496 83412 125118 162601 166824 250236 325202 487803 500472 650404 975606 1138207 1300808 1463409 1951212 2276414 2926818 3414621 3902424 4390227 4552828 5853636 6829242 8780454 9105656 10243863 11707272 13658484 17560908 20487726 27316968 30731589 35121816 40975452 53820931 61463178 81950904 107641862 122926356 161462793 215283724 245852712 322925586 376746517 430567448 484388379 645851172 753493034 968776758 1130239551 1291702344 1453165137 1506986068 1937553516 2260479102 2906330274 3013972136 3390718653 3875107032 4520958204 5812660548 6781437306 9041916408 10172155959 11625321096 13562874612 20344311918 27125749224 40688623836 81377247672