55663891 has 2 divisors, whose sum is σ = 55663892. Its totient is φ = 55663890.

The previous prime is 55663849. The next prime is 55663897. The reversal of 55663891 is 19836655.

55663891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 55663891 - 2⁹ = 55663379 is a prime.

It is a super-2 number, since 2×55663891² = 6196937522519762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (55663897) 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, 27831945 + 27831946.

It is an arithmetic number, because the mean of its divisors is an integer number (27831946).

Almost surely, 2^55663891 is an apocalyptic number.

55663891 is a deficient number, since it is larger than the sum of its proper divisors (1).

55663891 is an equidigital number, since it uses as much as digits as its factorization.

55663891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 194400, while the sum is 43.

The square root of 55663891 is about 7460.8237480857. The cubic root of 55663891 is about 381.8192793911.

The spelling of 55663891 in words is "fifty-five million, six hundred sixty-three thousand, eight hundred ninety-one".