31311157 has 2 divisors, whose sum is σ = 31311158. Its totient is φ = 31311156.

The previous prime is 31311143. The next prime is 31311173. The reversal of 31311157 is 75111313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23726641 + 7584516 = 4871^2 + 2754^2 .

It is a cyclic number.

It is not a de Polignac number, because 31311157 - 2⁷ = 31311029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31311187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15655578 + 15655579.

It is an arithmetic number, because the mean of its divisors is an integer number (15655579).

Almost surely, 2^31311157 is an apocalyptic number.

It is an amenable number.

31311157 is a deficient number, since it is larger than the sum of its proper divisors (1).

31311157 is an equidigital number, since it uses as much as digits as its factorization.

31311157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 315, while the sum is 22.

The square root of 31311157 is about 5595.6373184830. The cubic root of 31311157 is about 315.1856032241.

The spelling of 31311157 in words is "thirty-one million, three hundred eleven thousand, one hundred fifty-seven".