55918809 has 16 divisors (see below), whose sum is σ = 83106240. Its totient is φ = 37160640.

The previous prime is 55918783. The next prime is 55918813. The reversal of 55918809 is 90881955.

55918809 is a `hidden beast` number, since 559 + 18 + 80 + 9 = 666.

It is not a de Polignac number, because 55918809 - 2⁵ = 55918777 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (55918829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5809 + ... + 12065.

It is an arithmetic number, because the mean of its divisors is an integer number (5194140).

Almost surely, 2^55918809 is an apocalyptic number.

It is an amenable number.

55918809 is a deficient number, since it is larger than the sum of its proper divisors (27187431).

55918809 is a wasteful number, since it uses less digits than its factorization.

55918809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6597 (or 6591 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 45.

The square root of 55918809 is about 7477.8880039755. Note that the first 3 decimals coincide. The cubic root of 55918809 is about 382.4012509405.

It can be divided in two parts, 5591 and 8809, that added together give a square (14400 = 120²).

The spelling of 55918809 in words is "fifty-five million, nine hundred eighteen thousand, eight hundred nine".