55108221 has 16 divisors (see below), whose sum is σ = 84639744. Its totient is φ = 31240944.

The previous prime is 55108217. The next prime is 55108247. The reversal of 55108221 is 12280155.

It is not a de Polignac number, because 55108221 - 2² = 55108217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 55108191 and 55108200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55108201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7665 + ... + 12998.

It is an arithmetic number, because the mean of its divisors is an integer number (5289984).

Almost surely, 2^55108221 is an apocalyptic number.

It is an amenable number.

55108221 is a deficient number, since it is larger than the sum of its proper divisors (29531523).

55108221 is a wasteful number, since it uses less digits than its factorization.

55108221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20800.

The product of its (nonzero) digits is 800, while the sum is 24.

The square root of 55108221 is about 7423.4911598250. The cubic root of 55108221 is about 380.5445125473.

Adding to 55108221 its reverse (12280155), we get a palindrome (67388376).

It can be divided in two parts, 5510 and 8221, that added together give a palindrome (13731).

The spelling of 55108221 in words is "fifty-five million, one hundred eight thousand, two hundred twenty-one".