31457857 has 2 divisors, whose sum is σ = 31457858. Its totient is φ = 31457856.

The previous prime is 31457849. The next prime is 31457861. The reversal of 31457857 is 75875413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26946481 + 4511376 = 5191^2 + 2124^2 .

It is a cyclic number.

It is not a de Polignac number, because 31457857 - 2³ = 31457849 is a prime.

It is not a weakly prime, because it can be changed into another prime (31457557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15728928 + 15728929.

It is an arithmetic number, because the mean of its divisors is an integer number (15728929).

Almost surely, 2^31457857 is an apocalyptic number.

It is an amenable number.

31457857 is a deficient number, since it is larger than the sum of its proper divisors (1).

31457857 is an equidigital number, since it uses as much as digits as its factorization.

31457857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 117600, while the sum is 40.

The square root of 31457857 is about 5608.7304267543. The cubic root of 31457857 is about 315.6770755757.

The spelling of 31457857 in words is "thirty-one million, four hundred fifty-seven thousand, eight hundred fifty-seven".