55222221 has 8 divisors (see below), whose sum is σ = 73682784. Its totient is φ = 36788240.

The previous prime is 55222207. The next prime is 55222229. The reversal of 55222221 is 12222255.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 55222221 - 2⁶ = 55222157 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 (55222229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1146 + ... + 10571.

It is an arithmetic number, because the mean of its divisors is an integer number (9210348).

Almost surely, 2^55222221 is an apocalyptic number.

It is an amenable number.

55222221 is a deficient number, since it is larger than the sum of its proper divisors (18460563).

55222221 is a wasteful number, since it uses less digits than its factorization.

55222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13291.

The product of its digits is 800, while the sum is 21.

The square root of 55222221 is about 7431.1655209664. The cubic root of 55222221 is about 380.8067371529.

Adding to 55222221 its reverse (12222255), we get a palindrome (67444476).

The spelling of 55222221 in words is "fifty-five million, two hundred twenty-two thousand, two hundred twenty-one".