55321920 has 224 divisors, whose sum is σ = 206044800. Its totient is φ = 13934592.

The previous prime is 55321909. The next prime is 55321991. The reversal of 55321920 is 2912355.

55321920 is a `hidden beast` number, since 553 + 21 + 92 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 163992 + ... + 164328.

Almost surely, 2^55321920 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 55321920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103022400).

55321920 is an abundant number, since it is smaller than the sum of its proper divisors (150722880).

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

55321920 is a wasteful number, since it uses less digits than its factorization.

55321920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382 (or 366 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 55321920 is about 7437.8706630325. The cubic root of 55321920 is about 381.0357707131.

The spelling of 55321920 in words is "fifty-five million, three hundred twenty-one thousand, nine hundred twenty".