55731618 has 16 divisors (see below), whose sum is σ = 123848160. Its totient is φ = 18577188.

The previous prime is 55731563. The next prime is 55731619. The reversal of 55731618 is 81613755.

55731618 is a `hidden beast` number, since 5 + 5 + 7 + 31 + 618 = 666.

It is not an unprimeable number, because it can be changed into a prime (55731619) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 515980 + ... + 516087.

It is an arithmetic number, because the mean of its divisors is an integer number (7740510).

Almost surely, 2^55731618 is an apocalyptic number.

55731618 is an abundant number, since it is smaller than the sum of its proper divisors (68116542).

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

55731618 is a wasteful number, since it uses less digits than its factorization.

55731618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1032078 (or 1032072 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 55731618 is about 7465.3612102831. The cubic root of 55731618 is about 381.9740715020.

The spelling of 55731618 in words is "fifty-five million, seven hundred thirty-one thousand, six hundred eighteen".