55721996 has 12 divisors (see below), whose sum is σ = 106378440. Its totient is φ = 25328160.

The previous prime is 55721959. The next prime is 55722047. The reversal of 55721996 is 69912755.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (44), and also a Moran number because the ratio is a prime number: 1266409 = 55721996 / (5 + 5 + 7 + 2 + 1 + 9 + 9 + 6).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 633161 + ... + 633248.

It is an arithmetic number, because the mean of its divisors is an integer number (8864870).

Almost surely, 2^55721996 is an apocalyptic number.

It is an amenable number.

55721996 is a deficient number, since it is larger than the sum of its proper divisors (50656444).

55721996 is a wasteful number, since it uses less digits than its factorization.

55721996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1266424 (or 1266422 counting only the distinct ones).

The product of its digits is 170100, while the sum is 44.

The square root of 55721996 is about 7464.7167394349. The cubic root of 55721996 is about 381.9520877749.

The spelling of 55721996 in words is "fifty-five million, seven hundred twenty-one thousand, nine hundred ninety-six".