55621680 has 80 divisors (see below), whose sum is σ = 176131584. Its totient is φ = 14513920.

The previous prime is 55621679. The next prime is 55621697. The reversal of 55621680 is 8612655.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8815 + ... + 13745.

Almost surely, 2^55621680 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 55621680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88065792).

55621680 is an abundant number, since it is smaller than the sum of its proper divisors (120509904).

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

55621680 is a wasteful number, since it uses less digits than its factorization.

55621680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4994 (or 4988 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 33.

The square root of 55621680 is about 7457.9943684613. The cubic root of 55621680 is about 381.7227413484.

The spelling of 55621680 in words is "fifty-five million, six hundred twenty-one thousand, six hundred eighty".