31369321 has 2 divisors, whose sum is σ = 31369322. Its totient is φ = 31369320.

The previous prime is 31369279. The next prime is 31369339. The reversal of 31369321 is 12396313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28355625 + 3013696 = 5325^2 + 1736^2 .

It is a cyclic number.

It is not a de Polignac number, because 31369321 - 2¹⁵ = 31336553 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31369321.

It is not a weakly prime, because it can be changed into another prime (31369021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15684660 + 15684661.

It is an arithmetic number, because the mean of its divisors is an integer number (15684661).

Almost surely, 2^31369321 is an apocalyptic number.

It is an amenable number.

31369321 is a deficient number, since it is larger than the sum of its proper divisors (1).

31369321 is an equidigital number, since it uses as much as digits as its factorization.

31369321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2916, while the sum is 28.

The square root of 31369321 is about 5600.8321703118. The cubic root of 31369321 is about 315.3806467522.

The spelling of 31369321 in words is "thirty-one million, three hundred sixty-nine thousand, three hundred twenty-one".