31320431213 has 2 divisors, whose sum is σ = 31320431214. Its totient is φ = 31320431212.

The previous prime is 31320431209. The next prime is 31320431227. The reversal of 31320431213 is 31213402313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19797052804 + 11523378409 = 140702^2 + 107347^2 .

It is a cyclic number.

It is not a de Polignac number, because 31320431213 - 2² = 31320431209 is a prime.

It is a super-2 number, since 2×31320431213² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31320431113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15660215606 + 15660215607.

It is an arithmetic number, because the mean of its divisors is an integer number (15660215607).

Almost surely, 2^31320431213 is an apocalyptic number.

It is an amenable number.

31320431213 is a deficient number, since it is larger than the sum of its proper divisors (1).

31320431213 is an equidigital number, since it uses as much as digits as its factorization.

31320431213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 23.

Adding to 31320431213 its reverse (31213402313), we get a palindrome (62533833526).

The spelling of 31320431213 in words is "thirty-one billion, three hundred twenty million, four hundred thirty-one thousand, two hundred thirteen".