55621764 has 81 divisors (see below), whose sum is σ = 155922949. Its totient is φ = 16705920.

The previous prime is 55621757. The next prime is 55621777. The reversal of 55621764 is 46712655.

It is a happy number.

The square root of 55621764 is 7458.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 980100 + 54641664 = 990^2 + 7392^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 492172 + ... + 492284.

Almost surely, 2^55621764 is an apocalyptic number.

55621764 is the 7458-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55621764

55621764 is an abundant number, since it is smaller than the sum of its proper divisors (100301185).

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

55621764 is a wasteful number, since it uses less digits than its factorization.

55621764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258 (or 129 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The cubic root of 55621764 is about 381.7229335079.

Multiplying 55621764 by its sum of digits (36), we get a square (2002383504 = 44748²).

55621764 divided by its sum of digits (36) gives a square (1545049 = 1243²).

The spelling of 55621764 in words is "fifty-five million, six hundred twenty-one thousand, seven hundred sixty-four".