55615220 has 12 divisors (see below), whose sum is σ = 116792004. Its totient is φ = 22246080.

The previous prime is 55615213. The next prime is 55615247. The reversal of 55615220 is 2251655.

It can be written as a sum of positive squares in 2 ways, for example, as 10510564 + 45104656 = 3242^2 + 6716^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 55615220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1390361 + ... + 1390400.

It is an arithmetic number, because the mean of its divisors is an integer number (9732667).

Almost surely, 2^55615220 is an apocalyptic number.

It is an amenable number.

55615220 is an abundant number, since it is smaller than the sum of its proper divisors (61176784).

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

55615220 is a wasteful number, since it uses less digits than its factorization.

55615220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2780770 (or 2780768 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 55615220 is about 7457.5612635767. The cubic root of 55615220 is about 381.7079627922.

Adding to 55615220 its reverse (2251655), we get a palindrome (57866875).

The spelling of 55615220 in words is "fifty-five million, six hundred fifteen thousand, two hundred twenty".