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31213201020 = 22354761421431
BaseRepresentation
bin11101000100011100…
…111010011001111100
32222120022010220022020
4131010130322121330
51002411034413040
622201131120140
72153330555031
oct350434723174
988508126266
1031213201020
1112268046a01
1260712a3050
132c3582c121
141721613388
15c2a3c0cd0
hex74473a67c

31213201020 has 192 divisors, whose sum is σ = 91146166272. Its totient is φ = 7975296000.

The previous prime is 31213201001. The next prime is 31213201039. The reversal of 31213201020 is 2010231213.

It is an interprime number because it is at equal distance from previous prime (31213201001) and next prime (31213201039).

It is a Harshad number since it is a multiple of its sum of digits (15).

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 63 ways as a sum of consecutive naturals, for example, 72420205 + ... + 72420635.

It is an arithmetic number, because the mean of its divisors is an integer number (474719616).

Almost surely, 231213201020 is an apocalyptic number.

31213201020 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 31213201020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45573083136).

31213201020 is an abundant number, since it is smaller than the sum of its proper divisors (59932965252).

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

31213201020 is a wasteful number, since it uses less digits than its factorization.

31213201020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972 (or 970 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 31213201020 its reverse (2010231213), we get a palindrome (33223432233).

The spelling of 31213201020 in words is "thirty-one billion, two hundred thirteen million, two hundred one thousand, twenty".