31881628816 has 40 divisors (see below), whose sum is σ = 66405214080. Its totient is φ = 14780502144.

The previous prime is 31881628789. The next prime is 31881628829. The reversal of 31881628816 is 61882618813.

It is a super-2 number, since 2×31881628816² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors.

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, 1101391 + ... + 1129966.

It is an arithmetic number, because the mean of its divisors is an integer number (1660130352).

Almost surely, 2^31881628816 is an apocalyptic number.

It is an amenable number.

31881628816 is an abundant number, since it is smaller than the sum of its proper divisors (34523585264).

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

31881628816 is a wasteful number, since it uses less digits than its factorization.

31881628816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2231431 (or 2231425 counting only the distinct ones).

The product of its digits is 884736, while the sum is 52.

The spelling of 31881628816 in words is "thirty-one billion, eight hundred eighty-one million, six hundred twenty-eight thousand, eight hundred sixteen".