31977990999 has 16 divisors (see below), whose sum is σ = 48655203040. Its totient is φ = 20742480000.

The previous prime is 31977990991. The next prime is 31977991027. The reversal of 31977990999 is 99909977913.

It is not a de Polignac number, because 31977990999 - 2³ = 31977990991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31977990991) 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 15 ways as a sum of consecutive naturals, for example, 16004002 + ... + 16005999.

It is an arithmetic number, because the mean of its divisors is an integer number (3040950190).

Almost surely, 2^31977990999 is an apocalyptic number.

31977990999 is a deficient number, since it is larger than the sum of its proper divisors (16677212041).

31977990999 is a wasteful number, since it uses less digits than its factorization.

31977990999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32010047 (or 32010041 counting only the distinct ones).

The product of its (nonzero) digits is 78121827, while the sum is 72.

The spelling of 31977990999 in words is "thirty-one billion, nine hundred seventy-seven million, nine hundred ninety thousand, nine hundred ninety-nine".