55646221 has 4 divisors (see below), whose sum is σ = 56408572. Its totient is φ = 54883872.

The previous prime is 55646207. The next prime is 55646233. The reversal of 55646221 is 12264655.

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 43494025 + 12152196 = 6595^2 + 3486^2 .

It is a cyclic number.

It is not a de Polignac number, because 55646221 - 2⁵ = 55646189 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 (55646251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 381066 + ... + 381211.

It is an arithmetic number, because the mean of its divisors is an integer number (14102143).

Almost surely, 2^55646221 is an apocalyptic number.

It is an amenable number.

55646221 is a deficient number, since it is larger than the sum of its proper divisors (762351).

55646221 is an equidigital number, since it uses as much as digits as its factorization.

55646221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 762350.

The product of its digits is 14400, while the sum is 31.

The square root of 55646221 is about 7459.6394684998. The cubic root of 55646221 is about 381.7788734202.

The spelling of 55646221 in words is "fifty-five million, six hundred forty-six thousand, two hundred twenty-one".