55921872 has 80 divisors (see below), whose sum is σ = 149454720. Its totient is φ = 18009600.

The previous prime is 55921871. The next prime is 55921903. The reversal of 55921872 is 27812955.

It is a self number, because there is not a number n which added to its sum of digits gives 55921872.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55921871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 207754 + ... + 208022.

It is an arithmetic number, because the mean of its divisors is an integer number (1868184).

Almost surely, 2^55921872 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 55921872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74727360).

55921872 is an abundant number, since it is smaller than the sum of its proper divisors (93532848).

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

55921872 is a wasteful number, since it uses less digits than its factorization.

55921872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412 (or 406 counting only the distinct ones).

The product of its digits is 50400, while the sum is 39.

The square root of 55921872 is about 7478.0928049871. The cubic root of 55921872 is about 382.4082329302.

The spelling of 55921872 in words is "fifty-five million, nine hundred twenty-one thousand, eight hundred seventy-two".