55555920 has 240 divisors, whose sum is σ = 217581312. Its totient is φ = 12441600.

The previous prime is 55555901. The next prime is 55555963. The reversal of 55555920 is 2955555.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 367845 + ... + 367995.

Almost surely, 2^55555920 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 55555920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108790656).

55555920 is an abundant number, since it is smaller than the sum of its proper divisors (162025392).

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

55555920 is a wasteful number, since it uses less digits than its factorization.

55555920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250 (or 241 counting only the distinct ones).

The product of its (nonzero) digits is 56250, while the sum is 36.

The square root of 55555920 is about 7453.5843726358. The cubic root of 55555920 is about 381.5722485521.

The spelling of 55555920 in words is "fifty-five million, five hundred fifty-five thousand, nine hundred twenty".