218644023231 has 12 divisors (see below), whose sum is σ = 315825683680. Its totient is φ = 145759664160.

The previous prime is 218644023223. The next prime is 218644023271. The reversal of 218644023231 is 132320446812.

218644023231 is a `hidden beast` number, since 2 + 1 + 8 + 644 + 0 + 2 + 3 + 2 + 3 + 1 = 666.

It is not a de Polignac number, because 218644023231 - 2³ = 218644023223 is a prime.

It is a super-2 number, since 2×218644023231² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218644023271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 262650 + ... + 711528.

Almost surely, 2^218644023231 is an apocalyptic number.

218644023231 is a deficient number, since it is larger than the sum of its proper divisors (97181660449).

218644023231 is a wasteful number, since it uses less digits than its factorization.

218644023231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503006 (or 503003 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The spelling of 218644023231 in words is "two hundred eighteen billion, six hundred forty-four million, twenty-three thousand, two hundred thirty-one".