55721330 has 24 divisors (see below), whose sum is σ = 116674668. Its totient is φ = 19104288.

The previous prime is 55721329. The next prime is 55721363. The reversal of 55721330 is 3312755.

It can be written as a sum of positive squares in 2 ways, for example, as 55160329 + 561001 = 7427^2 + 749^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 55721330.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56369 + ... + 57348.

Almost surely, 2^55721330 is an apocalyptic number.

55721330 is an abundant number, since it is smaller than the sum of its proper divisors (60953338).

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

55721330 is a wasteful number, since it uses less digits than its factorization.

55721330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113738 (or 113731 counting only the distinct ones).

The product of its (nonzero) digits is 3150, while the sum is 26.

The square root of 55721330 is about 7464.6721294374. The cubic root of 55721330 is about 381.9505660472.

The spelling of 55721330 in words is "fifty-five million, seven hundred twenty-one thousand, three hundred thirty".