55424221 has 4 divisors (see below), whose sum is σ = 55440000. Its totient is φ = 55408444.

The previous prime is 55424219. The next prime is 55424231. The reversal of 55424221 is 12242455.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12242455 = 5 ⋅2448491.

It is a cyclic number.

It is not a de Polignac number, because 55424221 - 2¹ = 55424219 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 (55424231) 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, 30 + ... + 10528.

It is an arithmetic number, because the mean of its divisors is an integer number (13860000).

Almost surely, 2^55424221 is an apocalyptic number.

It is an amenable number.

55424221 is a deficient number, since it is larger than the sum of its proper divisors (15779).

55424221 is a wasteful number, since it uses less digits than its factorization.

55424221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15778.

The product of its digits is 3200, while the sum is 25.

The square root of 55424221 is about 7444.7445221445. The cubic root of 55424221 is about 381.2704958613.

Adding to 55424221 its reverse (12242455), we get a palindrome (67666676).

The spelling of 55424221 in words is "fifty-five million, four hundred twenty-four thousand, two hundred twenty-one".