55757220 has 72 divisors (see below), whose sum is σ = 161485632. Its totient is φ = 14374080.

The previous prime is 55757201. The next prime is 55757239. The reversal of 55757220 is 2275755.

It is an interprime number because it is at equal distance from previous prime (55757201) and next prime (55757239).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 57177 + ... + 58143.

It is an arithmetic number, because the mean of its divisors is an integer number (2242856).

Almost surely, 2^55757220 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 55757220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80742816).

55757220 is an abundant number, since it is smaller than the sum of its proper divisors (105728412).

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

55757220 is a wasteful number, since it uses less digits than its factorization.

55757220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1041 (or 1008 counting only the distinct ones).

The product of its (nonzero) digits is 24500, while the sum is 33.

The square root of 55757220 is about 7467.0757328421. The cubic root of 55757220 is about 382.0325529855.

The spelling of 55757220 in words is "fifty-five million, seven hundred fifty-seven thousand, two hundred twenty".