55907221 has 4 divisors (see below), whose sum is σ = 56191212. Its totient is φ = 55623232.

The previous prime is 55907183. The next prime is 55907233. The reversal of 55907221 is 12270955.

55907221 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 40462321 + 15444900 = 6361^2 + 3930^2 .

It is a cyclic number.

It is not a de Polignac number, because 55907221 - 2¹³ = 55899029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55907251) 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, 141700 + ... + 142093.

It is an arithmetic number, because the mean of its divisors is an integer number (14047803).

Almost surely, 2^55907221 is an apocalyptic number.

It is an amenable number.

55907221 is a deficient number, since it is larger than the sum of its proper divisors (283991).

55907221 is a wasteful number, since it uses less digits than its factorization.

55907221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283990.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 55907221 is about 7477.1131461280. The cubic root of 55907221 is about 382.3748342368.

The spelling of 55907221 in words is "fifty-five million, nine hundred seven thousand, two hundred twenty-one".