31997182818 has 16 divisors (see below), whose sum is σ = 64222106976. Its totient is φ = 10627770720.

The previous prime is 31997182817. The next prime is 31997182871. The reversal of 31997182818 is 81828179913.

It is a super-2 number, since 2×31997182818² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31997182817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9487396 + ... + 9490767.

It is an arithmetic number, because the mean of its divisors is an integer number (4013881686).

Almost surely, 2^31997182818 is an apocalyptic number.

31997182818 is an abundant number, since it is smaller than the sum of its proper divisors (32224924158).

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

31997182818 is a wasteful number, since it uses less digits than its factorization.

31997182818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18978449.

The product of its digits is 1741824, while the sum is 57.

The spelling of 31997182818 in words is "thirty-one billion, nine hundred ninety-seven million, one hundred eighty-two thousand, eight hundred eighteen".