31393217 has 2 divisors, whose sum is σ = 31393218. Its totient is φ = 31393216.

The previous prime is 31393211. The next prime is 31393253. The reversal of 31393217 is 71239313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31013761 + 379456 = 5569^2 + 616^2 .

It is a cyclic number.

It is not a de Polignac number, because 31393217 - 2¹⁴ = 31376833 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31393217.

It is not a weakly prime, because it can be changed into another prime (31393211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15696608 + 15696609.

It is an arithmetic number, because the mean of its divisors is an integer number (15696609).

Almost surely, 2^31393217 is an apocalyptic number.

It is an amenable number.

31393217 is a deficient number, since it is larger than the sum of its proper divisors (1).

31393217 is an equidigital number, since it uses as much as digits as its factorization.

31393217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3402, while the sum is 29.

The square root of 31393217 is about 5602.9650186308. The cubic root of 31393217 is about 315.4607082355.

The spelling of 31393217 in words is "thirty-one million, three hundred ninety-three thousand, two hundred seventeen".