56857391 has 2 divisors, whose sum is σ = 56857392. Its totient is φ = 56857390.

The previous prime is 56857387. The next prime is 56857417. The reversal of 56857391 is 19375865.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 56857391 - 2² = 56857387 is a prime.

It is a super-2 number, since 2×56857391² = 6465525822653762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56857301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28428695 + 28428696.

It is an arithmetic number, because the mean of its divisors is an integer number (28428696).

Almost surely, 2^56857391 is an apocalyptic number.

56857391 is a deficient number, since it is larger than the sum of its proper divisors (1).

56857391 is an equidigital number, since it uses as much as digits as its factorization.

56857391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 226800, while the sum is 44.

The square root of 56857391 is about 7540.3840087889. The cubic root of 56857391 is about 384.5288913476.

The spelling of 56857391 in words is "fifty-six million, eight hundred fifty-seven thousand, three hundred ninety-one".