31313617 has 2 divisors, whose sum is σ = 31313618. Its totient is φ = 31313616.

The previous prime is 31313599. The next prime is 31313641. The reversal of 31313617 is 71631313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31091776 + 221841 = 5576^2 + 471^2 .

It is a cyclic number.

It is not a de Polignac number, because 31313617 - 2⁷ = 31313489 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31313591 and 31313600.

It is not a weakly prime, because it can be changed into another prime (31313687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15656808 + 15656809.

It is an arithmetic number, because the mean of its divisors is an integer number (15656809).

Almost surely, 2^31313617 is an apocalyptic number.

It is an amenable number.

31313617 is a deficient number, since it is larger than the sum of its proper divisors (1).

31313617 is an equidigital number, since it uses as much as digits as its factorization.

31313617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1134, while the sum is 25.

The square root of 31313617 is about 5595.8571282691. The cubic root of 31313617 is about 315.1938573242.

The spelling of 31313617 in words is "thirty-one million, three hundred thirteen thousand, six hundred seventeen".