55655721 has 16 divisors (see below), whose sum is σ = 89949120. Its totient is φ = 33730560.

The previous prime is 55655701. The next prime is 55655749. The reversal of 55655721 is 12755655.

It is a happy number.

55655721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 55655721 - 2¹⁸ = 55393577 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (55655701) by changing a digit.

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, 93400 + ... + 93993.

It is an arithmetic number, because the mean of its divisors is an integer number (5621820).

Almost surely, 2^55655721 is an apocalyptic number.

It is an amenable number.

55655721 is a deficient number, since it is larger than the sum of its proper divisors (34293399).

55655721 is a wasteful number, since it uses less digits than its factorization.

55655721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187413 (or 187407 counting only the distinct ones).

The product of its digits is 52500, while the sum is 36.

The square root of 55655721 is about 7460.2762013212. The cubic root of 55655721 is about 381.8005981234.

The spelling of 55655721 in words is "fifty-five million, six hundred fifty-five thousand, seven hundred twenty-one".