57057991 has 2 divisors, whose sum is σ = 57057992. Its totient is φ = 57057990.

The previous prime is 57057977. The next prime is 57058021. The reversal of 57057991 is 19975075.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 57057991 - 2¹⁹ = 56533703 is a prime.

It is a super-2 number, since 2×57057991² = 6511228673912162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (57057901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28528995 + 28528996.

It is an arithmetic number, because the mean of its divisors is an integer number (28528996).

Almost surely, 2^57057991 is an apocalyptic number.

57057991 is a deficient number, since it is larger than the sum of its proper divisors (1).

57057991 is an equidigital number, since it uses as much as digits as its factorization.

57057991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 99225, while the sum is 43.

The square root of 57057991 is about 7553.6740067334. The cubic root of 57057991 is about 384.9805825930.

The spelling of 57057991 in words is "fifty-seven million, fifty-seven thousand, nine hundred ninety-one".