221521222 has 16 divisors (see below), whose sum is σ = 358751232. Its totient is φ = 101980800.

The previous prime is 221521217. The next prime is 221521241. The reversal of 221521222 is 222125122.

It is a self number, because there is not a number n which added to its sum of digits gives 221521222.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 198 + ... + 21049.

It is an arithmetic number, because the mean of its divisors is an integer number (22421952).

Almost surely, 2^221521222 is an apocalyptic number.

221521222 is a deficient number, since it is larger than the sum of its proper divisors (137230010).

221521222 is a wasteful number, since it uses less digits than its factorization.

221521222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21663.

The product of its digits is 320, while the sum is 19.

The square root of 221521222 is about 14883.5890160942. The cubic root of 221521222 is about 605.0692924300.

Adding to 221521222 its reverse (222125122), we get a palindrome (443646344).

The spelling of 221521222 in words is "two hundred twenty-one million, five hundred twenty-one thousand, two hundred twenty-two".