55721172 has 48 divisors (see below), whose sum is σ = 148260672. Its totient is φ = 16135680.

The previous prime is 55721161. The next prime is 55721191. The reversal of 55721172 is 27112755.

55721172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7854 + ... + 13157.

It is an arithmetic number, because the mean of its divisors is an integer number (3088764).

Almost surely, 2^55721172 is an apocalyptic number.

55721172 is a gapful number since it is divisible by the number (52) formed by its first and last digit.

It is an amenable number.

55721172 is an abundant number, since it is smaller than the sum of its proper divisors (92539500).

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

55721172 is a wasteful number, since it uses less digits than its factorization.

55721172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21048 (or 21046 counting only the distinct ones).

The product of its digits is 4900, while the sum is 30.

The square root of 55721172 is about 7464.6615462458. The cubic root of 55721172 is about 381.9502050350.

The spelling of 55721172 in words is "fifty-five million, seven hundred twenty-one thousand, one hundred seventy-two".