55721190 has 32 divisors (see below), whose sum is σ = 152835840. Its totient is φ = 12736224.

The previous prime is 55721161. The next prime is 55721191. The reversal of 55721190 is 9112755.

It is a super-2 number, since 2×55721190² = 6209702030032200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55721191) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 132460 + ... + 132879.

It is an arithmetic number, because the mean of its divisors is an integer number (4776120).

Almost surely, 2^55721190 is an apocalyptic number.

55721190 is an abundant number, since it is smaller than the sum of its proper divisors (97114650).

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

55721190 is a wasteful number, since it uses less digits than its factorization.

55721190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265356.

The product of its (nonzero) digits is 3150, while the sum is 30.

The square root of 55721190 is about 7464.6627519266. The cubic root of 55721190 is about 381.9502461630.

The spelling of 55721190 in words is "fifty-five million, seven hundred twenty-one thousand, one hundred ninety".