Adding to 55413221 its reverse (12231455), we get a palindrome (67644676).
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 2k-55413221 is a prime.
It is a Duffinian number.
It is a congruent number.
Almost surely, 255413221 is an apocalyptic number.
It is an amenable number.
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 square root of 55413221 is about 7444.0057092939. The cubic root of 55413221 is about 381.2452707108.
The spelling of 55413221 in words is "fifty-five million, four hundred thirteen thousand, two hundred twenty-one".