55521900 has 162 divisors, whose sum is σ = 202604220. Its totient is φ = 12680640.

The previous prime is 55521887. The next prime is 55521923. The reversal of 55521900 is 912555.

55521900 is a `hidden beast` number, since 55 + 521 + 90 + 0 = 666.

It is a super-2 number, since 2×55521900² = 6165362759220000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 43471 + ... + 44729.

Almost surely, 2^55521900 is an apocalyptic number.

55521900 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55521900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101302110).

55521900 is an abundant number, since it is smaller than the sum of its proper divisors (147082320).

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

55521900 is a wasteful number, since it uses less digits than its factorization.

55521900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1293 (or 1276 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 27.

The square root of 55521900 is about 7451.3018996683. The cubic root of 55521900 is about 381.4943466323.

The spelling of 55521900 in words is "fifty-five million, five hundred twenty-one thousand, nine hundred".