55218 has 8 divisors (see below), whose sum is σ = 110448. Its totient is φ = 18404.

The previous prime is 55217. The next prime is 55219. The reversal of 55218 is 81255.

It is an interprime number because it is at equal distance from previous prime (55217) and next prime (55219).

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

55218 is an admirable number.

It is an Ulam number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 55194 and 55203.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 55218.

It is not an unprimeable number, because it can be changed into a prime (55213) 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, 4596 + ... + 4607.

It is an arithmetic number, because the mean of its divisors is an integer number (13806).

2⁵⁵²¹⁸ is an apocalyptic number.

55218 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55224).

55218 is a wasteful number, since it uses less digits than its factorization.

55218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9208.

The product of its digits is 400, while the sum is 21.

The square root of 55218 is about 234.9851059110. The cubic root of 55218 is about 38.0797034379.

The spelling of 55218 in words is "fifty-five thousand, two hundred eighteen".