31687922664864 has 144 divisors (see below), whose sum is σ = 90962531700768. Its totient is φ = 10463024011776.

The previous prime is 31687922664857. The next prime is 31687922664869. The reversal of 31687922664864 is 46846622978613.

31687922664864 is a `hidden beast` number, since 3 + 1 + 6 + 87 + 9 + 2 + 2 + 66 + 486 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 31687922664792 and 31687922664801.

It is not an unprimeable number, because it can be changed into a prime (31687922664869) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 423898339 + ... + 423973085.

It is an arithmetic number, because the mean of its divisors is an integer number (631684247922).

Almost surely, 2^{31687922664864} 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 31687922664864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45481265850384).

31687922664864 is an abundant number, since it is smaller than the sum of its proper divisors (59274609035904).

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

31687922664864 is a wasteful number, since it uses less digits than its factorization.

31687922664864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88627 (or 88616 counting only the distinct ones).

The product of its digits is 1003290624, while the sum is 72.

The spelling of 31687922664864 in words is "thirty-one trillion, six hundred eighty-seven billion, nine hundred twenty-two million, six hundred sixty-four thousand, eight hundred sixty-four".