31213021213 has 12 divisors (see below), whose sum is σ = 34321355964. Its totient is φ = 28364864000.

The previous prime is 31213021157. The next prime is 31213021219. The reversal of 31213021213 is 31212031213.

It can be written as a sum of positive squares in 2 ways, for example, as 29741761764 + 1471259449 = 172458^2 + 38357^2 .

It is not a de Polignac number, because 31213021213 - 2⁹ = 31213020701 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 (31213021219) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 286263 + ... + 379963.

It is an arithmetic number, because the mean of its divisors is an integer number (2860112997).

Almost surely, 2^31213021213 is an apocalyptic number.

It is an amenable number.

31213021213 is a deficient number, since it is larger than the sum of its proper divisors (3108334751).

31213021213 is a wasteful number, since it uses less digits than its factorization.

31213021213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96476 (or 96465 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 31213021213 its reverse (31212031213), we get a palindrome (62425052426).

The spelling of 31213021213 in words is "thirty-one billion, two hundred thirteen million, twenty-one thousand, two hundred thirteen".