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31556131981920 = 25355713171953521
BaseRepresentation
bin1110010110011001111000…
…00010011000101001100000
311010201201220002120000200000
413023030330002120221200
513114003424241410140
6151040404212100000
76434566240112640
oct713147402305140
9133651802500600
1031556131981920
11a066975923247
123657958904600
13147b965b21c30
147b14798b0520
1539acaa021a30
hex1cb33c098a60

31556131981920 has 4608 divisors, whose sum is σ = 156378833694720. Its totient is φ = 5813352529920.

The previous prime is 31556131981919. The next prime is 31556131981987. The reversal of 31556131981920 is 2918913165513.

It is a happy number.

31556131981920 is a `hidden beast` number, since 3 + 1 + 5 + 5 + 613 + 1 + 9 + 8 + 19 + 2 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 767 ways as a sum of consecutive naturals, for example, 60568391260 + ... + 60568391780.

It is an arithmetic number, because the mean of its divisors is an integer number (33936378840).

Almost surely, 231556131981920 is an apocalyptic number.

31556131981920 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31556131981920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78189416847360).

31556131981920 is an abundant number, since it is smaller than the sum of its proper divisors (124822701712800).

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

31556131981920 is a wasteful number, since it uses less digits than its factorization.

31556131981920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660 (or 640 counting only the distinct ones).

The product of its (nonzero) digits is 1749600, while the sum is 54.

The spelling of 31556131981920 in words is "thirty-one trillion, five hundred fifty-six billion, one hundred thirty-one million, nine hundred eighty-one thousand, nine hundred twenty".