55447891 has 2 divisors, whose sum is σ = 55447892. Its totient is φ = 55447890.

The previous prime is 55447883. The next prime is 55447919. The reversal of 55447891 is 19874455.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55447891 - 2³ = 55447883 is a prime.

It is not a weakly prime, because it can be changed into another prime (55447811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27723945 + 27723946.

It is an arithmetic number, because the mean of its divisors is an integer number (27723946).

Almost surely, 2^55447891 is an apocalyptic number.

55447891 is a deficient number, since it is larger than the sum of its proper divisors (1).

55447891 is an equidigital number, since it uses as much as digits as its factorization.

55447891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 201600, while the sum is 43.

The square root of 55447891 is about 7446.3340644911. The cubic root of 55447891 is about 381.3247644829.

The spelling of 55447891 in words is "fifty-five million, four hundred forty-seven thousand, eight hundred ninety-one".