55213618 has 8 divisors (see below), whose sum is σ = 83453040. Its totient is φ = 27395940.

The previous prime is 55213607. The next prime is 55213619. The reversal of 55213618 is 81631255.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×55213618² = 6097087225299848, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 55213618.

It is not an unprimeable number, because it can be changed into a prime (55213619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105108 + ... + 105631.

It is an arithmetic number, because the mean of its divisors is an integer number (10431630).

Almost surely, 2^55213618 is an apocalyptic number.

55213618 is a deficient number, since it is larger than the sum of its proper divisors (28239422).

55213618 is a wasteful number, since it uses less digits than its factorization.

55213618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210872.

The product of its digits is 7200, while the sum is 31.

The square root of 55213618 is about 7430.5866524791. The cubic root of 55213618 is about 380.7869609925.

The spelling of 55213618 in words is "fifty-five million, two hundred thirteen thousand, six hundred eighteen".