55495721 has 4 divisors (see below), whose sum is σ = 55578372. Its totient is φ = 55413072.

The previous prime is 55495697. The next prime is 55495733. The reversal of 55495721 is 12759455.

It is a happy number.

55495721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37687321 + 17808400 = 6139^2 + 4220^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55495721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55495771) 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 3 ways as a sum of consecutive naturals, for example, 40310 + ... + 41663.

It is an arithmetic number, because the mean of its divisors is an integer number (13894593).

Almost surely, 2^55495721 is an apocalyptic number.

It is an amenable number.

55495721 is a deficient number, since it is larger than the sum of its proper divisors (82651).

55495721 is an equidigital number, since it uses as much as digits as its factorization.

55495721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82650.

The product of its digits is 63000, while the sum is 38.

The square root of 55495721 is about 7449.5450196640. The cubic root of 55495721 is about 381.4343780398.

The spelling of 55495721 in words is "fifty-five million, four hundred ninety-five thousand, seven hundred twenty-one".