221220055 has 24 divisors (see below), whose sum is σ = 309646800. Its totient is φ = 151280640.

The previous prime is 221220037. The next prime is 221220067. The reversal of 221220055 is 550022122.

It is not a de Polignac number, because 221220055 - 2⁷ = 221219927 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 109000 + ... + 111010.

It is an arithmetic number, because the mean of its divisors is an integer number (12901950).

Almost surely, 2^221220055 is an apocalyptic number.

221220055 is a deficient number, since it is larger than the sum of its proper divisors (88426745).

221220055 is a wasteful number, since it uses less digits than its factorization.

221220055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2479 (or 2472 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 221220055 is about 14873.4681564187. The cubic root of 221220055 is about 604.7949627353.

Adding to 221220055 its reverse (550022122), we get a palindrome (771242177).

The spelling of 221220055 in words is "two hundred twenty-one million, two hundred twenty thousand, fifty-five".