56571391 has 2 divisors, whose sum is σ = 56571392. Its totient is φ = 56571390.

The previous prime is 56571371. The next prime is 56571419. The reversal of 56571391 is 19317565.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56571391 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 56571391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56571301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28285695 + 28285696.

It is an arithmetic number, because the mean of its divisors is an integer number (28285696).

Almost surely, 2^56571391 is an apocalyptic number.

56571391 is a deficient number, since it is larger than the sum of its proper divisors (1).

56571391 is an equidigital number, since it uses as much as digits as its factorization.

56571391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28350, while the sum is 37.

The square root of 56571391 is about 7521.3955486997. The cubic root of 56571391 is about 383.8830639854.

The spelling of 56571391 in words is "fifty-six million, five hundred seventy-one thousand, three hundred ninety-one".