56663891 has 2 divisors, whose sum is σ = 56663892. Its totient is φ = 56663890.

The previous prime is 56663863. The next prime is 56663899. The reversal of 56663891 is 19836665.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56663891 is a prime.

It is not a weakly prime, because it can be changed into another prime (56663899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28331945 + 28331946.

It is an arithmetic number, because the mean of its divisors is an integer number (28331946).

Almost surely, 2^56663891 is an apocalyptic number.

56663891 is a deficient number, since it is larger than the sum of its proper divisors (1).

56663891 is an equidigital number, since it uses as much as digits as its factorization.

56663891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 44.

The square root of 56663891 is about 7527.5421619543. The cubic root of 56663891 is about 384.0921793860.

The spelling of 56663891 in words is "fifty-six million, six hundred sixty-three thousand, eight hundred ninety-one".