813931213 has 2 divisors, whose sum is σ = 813931214. Its totient is φ = 813931212.

The previous prime is 813931207. The next prime is 813931241. The reversal of 813931213 is 312139318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 439237764 + 374693449 = 20958^2 + 19357^2 .

It is a cyclic number.

It is not a de Polignac number, because 813931213 - 2²⁵ = 780376781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (813941213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 406965606 + 406965607.

It is an arithmetic number, because the mean of its divisors is an integer number (406965607).

Almost surely, 2^813931213 is an apocalyptic number.

It is an amenable number.

813931213 is a deficient number, since it is larger than the sum of its proper divisors (1).

813931213 is an equidigital number, since it uses as much as digits as its factorization.

813931213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 31.

The square root of 813931213 is about 28529.4797183545. The cubic root of 813931213 is about 933.6753671442.

The spelling of 813931213 in words is "eight hundred thirteen million, nine hundred thirty-one thousand, two hundred thirteen".