31997189680 has 80 divisors (see below), whose sum is σ = 79092884160. Its totient is φ = 12011377664.

The previous prime is 31997189629. The next prime is 31997189683. The reversal of 31997189680 is 8698179913.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (31997189683) 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, 66535 + ... + 261574.

It is an arithmetic number, because the mean of its divisors is an integer number (988661052).

Almost surely, 2^31997189680 is an apocalyptic number.

It is an amenable number.

31997189680 is an abundant number, since it is smaller than the sum of its proper divisors (47095694480).

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

31997189680 is a wasteful number, since it uses less digits than its factorization.

31997189680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328198 (or 328192 counting only the distinct ones).

The product of its (nonzero) digits is 5878656, while the sum is 61.

The spelling of 31997189680 in words is "thirty-one billion, nine hundred ninety-seven million, one hundred eighty-nine thousand, six hundred eighty".