55721995 has 32 divisors (see below), whose sum is σ = 78556032. Its totient is φ = 37158912.

The previous prime is 55721959. The next prime is 55722047. The reversal of 55721995 is 59912755.

It is a happy number.

It is not a de Polignac number, because 55721995 - 2⁹ = 55721483 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 288619 + ... + 288811.

It is an arithmetic number, because the mean of its divisors is an integer number (2454876).

Almost surely, 2^55721995 is an apocalyptic number.

55721995 is a deficient number, since it is larger than the sum of its proper divisors (22834037).

55721995 is a wasteful number, since it uses less digits than its factorization.

55721995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391.

The product of its digits is 141750, while the sum is 43.

The square root of 55721995 is about 7464.7166724531. The cubic root of 55721995 is about 381.9520854900.

The spelling of 55721995 in words is "fifty-five million, seven hundred twenty-one thousand, nine hundred ninety-five".