31928857 has 2 divisors, whose sum is σ = 31928858. Its totient is φ = 31928856.

The previous prime is 31928789. The next prime is 31928863. The reversal of 31928857 is 75882913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23970816 + 7958041 = 4896^2 + 2821^2 .

It is a cyclic number.

It is not a de Polignac number, because 31928857 - 2¹¹ = 31926809 is a prime.

It is not a weakly prime, because it can be changed into another prime (31928657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15964428 + 15964429.

It is an arithmetic number, because the mean of its divisors is an integer number (15964429).

Almost surely, 2^31928857 is an apocalyptic number.

It is an amenable number.

31928857 is a deficient number, since it is larger than the sum of its proper divisors (1).

31928857 is an equidigital number, since it uses as much as digits as its factorization.

31928857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 43.

The square root of 31928857 is about 5650.5625383673. The cubic root of 31928857 is about 317.2447598358.

The spelling of 31928857 in words is "thirty-one million, nine hundred twenty-eight thousand, eight hundred fifty-seven".