55621872 has 30 divisors (see below), whose sum is σ = 155664392. Its totient is φ = 18540576.

The previous prime is 55621861. The next prime is 55621879. The reversal of 55621872 is 27812655.

It is a happy number.

55621872 is a `hidden beast` number, since 556 + 21 + 87 + 2 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55621879) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 192988 + ... + 193275.

Almost surely, 2^55621872 is an apocalyptic number.

It is an amenable number.

55621872 is an abundant number, since it is smaller than the sum of its proper divisors (100042520).

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

55621872 is a wasteful number, since it uses less digits than its factorization.

55621872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386277 (or 386268 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 55621872 is about 7458.0072405435. The cubic root of 55621872 is about 381.7231805698.

The spelling of 55621872 in words is "fifty-five million, six hundred twenty-one thousand, eight hundred seventy-two".