31815861121 has 12 divisors (see below), whose sum is σ = 35784441616. Its totient is φ = 28250865720.

The previous prime is 31815861113. The next prime is 31815861137. The reversal of 31815861121 is 12116851813.

It is not a de Polignac number, because 31815861121 - 2³ = 31815861113 is a prime.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (31815861221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3052251 + ... + 3062656.

Almost surely, 2^31815861121 is an apocalyptic number.

It is an amenable number.

31815861121 is a deficient number, since it is larger than the sum of its proper divisors (3968580495).

31815861121 is a wasteful number, since it uses less digits than its factorization.

31815861121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6114972 (or 6114961 counting only the distinct ones).

The product of its digits is 11520, while the sum is 37.

The spelling of 31815861121 in words is "thirty-one billion, eight hundred fifteen million, eight hundred sixty-one thousand, one hundred twenty-one".