31717913 has 2 divisors, whose sum is σ = 31717914. Its totient is φ = 31717912.

The previous prime is 31717891. The next prime is 31717949. The reversal of 31717913 is 31971713.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19829209 + 11888704 = 4453^2 + 3448^2 .

It is a cyclic number.

It is not a de Polignac number, because 31717913 - 2⁶ = 31717849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31717913.

It is not a weakly prime, because it can be changed into another prime (31717963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15858956 + 15858957.

It is an arithmetic number, because the mean of its divisors is an integer number (15858957).

Almost surely, 2^31717913 is an apocalyptic number.

It is an amenable number.

31717913 is a deficient number, since it is larger than the sum of its proper divisors (1).

31717913 is an equidigital number, since it uses as much as digits as its factorization.

31717913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3969, while the sum is 32.

The square root of 31717913 is about 5631.8658542263. The cubic root of 31717913 is about 316.5445698576.

The spelling of 31717913 in words is "thirty-one million, seven hundred seventeen thousand, nine hundred thirteen".