31616816618 has 4 divisors (see below), whose sum is σ = 47425224930. Its totient is φ = 15808408308.

The previous prime is 31616816599. The next prime is 31616816633. The reversal of 31616816618 is 81661861613.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16196889289 + 15419927329 = 127267^2 + 124177^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7904204153 + ... + 7904204156.

Almost surely, 2^31616816618 is an apocalyptic number.

31616816618 is a deficient number, since it is larger than the sum of its proper divisors (15808408312).

31616816618 is a wasteful number, since it uses less digits than its factorization.

31616816618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15808408311.

The product of its digits is 248832, while the sum is 47.

The spelling of 31616816618 in words is "thirty-one billion, six hundred sixteen million, eight hundred sixteen thousand, six hundred eighteen".