3991556231068 has 24 divisors (see below), whose sum is σ = 7984394415200. Its totient is φ = 1710392251968.

The previous prime is 3991556231053. The next prime is 3991556231071. The reversal of 3991556231068 is 8601326551993.

It is a super-2 number, since 2×3991556231068² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11268483 + ... + 11617306.

Almost surely, 2^{3991556231068} is an apocalyptic number.

It is an amenable number.

3991556231068 is an abundant number, since it is smaller than the sum of its proper divisors (3992838184132).

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

3991556231068 is a wasteful number, since it uses less digits than its factorization.

3991556231068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22892029 (or 22892027 counting only the distinct ones).

The product of its (nonzero) digits is 10497600, while the sum is 58.

The spelling of 3991556231068 in words is "three trillion, nine hundred ninety-one billion, five hundred fifty-six million, two hundred thirty-one thousand, sixty-eight".