55921818 has 16 divisors (see below), whose sum is σ = 113513760. Its totient is φ = 18362256.

The previous prime is 55921777. The next prime is 55921841. The reversal of 55921818 is 81812955.

55921818 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 69153 + ... + 69956.

It is an arithmetic number, because the mean of its divisors is an integer number (7094610).

Almost surely, 2^55921818 is an apocalyptic number.

55921818 is an abundant number, since it is smaller than the sum of its proper divisors (57591942).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55921818 is a wasteful number, since it uses less digits than its factorization.

55921818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139181.

The product of its digits is 28800, while the sum is 39.

The square root of 55921818 is about 7478.0891944400. The cubic root of 55921818 is about 382.4081098415.

The spelling of 55921818 in words is "fifty-five million, nine hundred twenty-one thousand, eight hundred eighteen".