31317857 has 2 divisors, whose sum is σ = 31317858. Its totient is φ = 31317856.

The previous prime is 31317851. The next prime is 31317899. The reversal of 31317857 is 75871313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17172736 + 14145121 = 4144^2 + 3761^2 .

It is a cyclic number.

It is not a de Polignac number, because 31317857 - 2¹⁰ = 31316833 is a prime.

It is not a weakly prime, because it can be changed into another prime (31317851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15658928 + 15658929.

It is an arithmetic number, because the mean of its divisors is an integer number (15658929).

Almost surely, 2^31317857 is an apocalyptic number.

It is an amenable number.

31317857 is a deficient number, since it is larger than the sum of its proper divisors (1).

31317857 is an equidigital number, since it uses as much as digits as its factorization.

31317857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17640, while the sum is 35.

The square root of 31317857 is about 5596.2359671479. The cubic root of 31317857 is about 315.2080828888.

The spelling of 31317857 in words is "thirty-one million, three hundred seventeen thousand, eight hundred fifty-seven".