55444221 has 12 divisors (see below), whose sum is σ = 91527072. Its totient is φ = 31682376.

The previous prime is 55444217. The next prime is 55444273. The reversal of 55444221 is 12244455.

It is not a de Polignac number, because 55444221 - 2² = 55444217 is a prime.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55444321) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 439971 + ... + 440096.

It is an arithmetic number, because the mean of its divisors is an integer number (7627256).

Almost surely, 2^55444221 is an apocalyptic number.

It is an amenable number.

55444221 is a deficient number, since it is larger than the sum of its proper divisors (36082851).

55444221 is a wasteful number, since it uses less digits than its factorization.

55444221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 880080 (or 880077 counting only the distinct ones).

The product of its digits is 6400, while the sum is 27.

The square root of 55444221 is about 7446.0876304271. The cubic root of 55444221 is about 381.3163512217.

Adding to 55444221 its reverse (12244455), we get a palindrome (67688676).

The spelling of 55444221 in words is "fifty-five million, four hundred forty-four thousand, two hundred twenty-one".