31800018031656 has 32 divisors (see below), whose sum is σ = 90857194376640. Its totient is φ = 9085719437568.

The previous prime is 31800018031631. The next prime is 31800018031657. The reversal of 31800018031656 is 65613081000813.

It is a super-2 number, since 2×31800018031656² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (31800018031657) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 94642910641 + ... + 94642910976.

It is an arithmetic number, because the mean of its divisors is an integer number (2839287324270).

Almost surely, 2^{31800018031656} is an apocalyptic number.

It is an amenable number.

31800018031656 is an abundant number, since it is smaller than the sum of its proper divisors (59057176344984).

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

31800018031656 is a wasteful number, since it uses less digits than its factorization.

31800018031656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189285821633 (or 189285821629 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 42.

The spelling of 31800018031656 in words is "thirty-one trillion, eight hundred billion, eighteen million, thirty-one thousand, six hundred fifty-six".