55660220 has 96 divisors (see below), whose sum is σ = 149022720. Its totient is φ = 16957440.

The previous prime is 55660219. The next prime is 55660259. The reversal of 55660220 is 2206655.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 55660220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 71996 + ... + 72764.

It is an arithmetic number, because the mean of its divisors is an integer number (1552320).

Almost surely, 2^55660220 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55660220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74511360).

55660220 is an abundant number, since it is smaller than the sum of its proper divisors (93362500).

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

55660220 is a wasteful number, since it uses less digits than its factorization.

55660220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843 (or 841 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 55660220 is about 7460.5777256188. The cubic root of 55660220 is about 381.8108856230.

Adding to 55660220 its reverse (2206655), we get a palindrome (57866875).

The spelling of 55660220 in words is "fifty-five million, six hundred sixty thousand, two hundred twenty".