31221133130218 has 16 divisors (see below), whose sum is σ = 49598445708360. Its totient is φ = 14688760121856.

The previous prime is 31221133130189. The next prime is 31221133130219. The reversal of 31221133130218 is 81203133112213.

It can be written as a sum of positive squares in 4 ways, for example, as 27300760850169 + 3920372280049 = 5225013^2 + 1979993^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 31221133130218.

It is not an unprimeable number, because it can be changed into a prime (31221133130219) 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, 110413653 + ... + 110696056.

Almost surely, 2^{31221133130218} is an apocalyptic number.

31221133130218 is a deficient number, since it is larger than the sum of its proper divisors (18377312578142).

31221133130218 is a wasteful number, since it uses less digits than its factorization.

31221133130218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221113881.

The product of its (nonzero) digits is 5184, while the sum is 31.

The spelling of 31221133130218 in words is "thirty-one trillion, two hundred twenty-one billion, one hundred thirty-three million, one hundred thirty thousand, two hundred eighteen".