55413221 has 4 divisors (see below), whose sum is σ = 56240352. Its totient is φ = 54586092.

The previous prime is 55413199. The next prime is 55413223. The reversal of 55413221 is 12231455.

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: 12231455 = 5 ⋅2446291.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55413221 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 (55413223) 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, 413465 + ... + 413598.

It is an arithmetic number, because the mean of its divisors is an integer number (14060088).

Almost surely, 2^55413221 is an apocalyptic number.

It is an amenable number.

55413221 is a deficient number, since it is larger than the sum of its proper divisors (827131).

55413221 is an equidigital number, since it uses as much as digits as its factorization.

55413221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 827130.

The product of its digits is 1200, while the sum is 23.

The square root of 55413221 is about 7444.0057092939. The cubic root of 55413221 is about 381.2452707108.

Adding to 55413221 its reverse (12231455), we get a palindrome (67644676).

The spelling of 55413221 in words is "fifty-five million, four hundred thirteen thousand, two hundred twenty-one".