221221120228 has 6 divisors (see below), whose sum is σ = 387136960406. Its totient is φ = 110610560112.

The previous prime is 221221120217. The next prime is 221221120229. The reversal of 221221120228 is 822021122122.

It can be written as a sum of positive squares in only one way, i.e., 139008174244 + 82212945984 = 372838^2 + 286728^2 .

It is not an unprimeable number, because it can be changed into a prime (221221120229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27652640025 + ... + 27652640032.

Almost surely, 2^221221120228 is an apocalyptic number.

It is an amenable number.

221221120228 is a deficient number, since it is larger than the sum of its proper divisors (165915840178).

221221120228 is a wasteful number, since it uses less digits than its factorization.

221221120228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55305280061 (or 55305280059 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 25.

The spelling of 221221120228 in words is "two hundred twenty-one billion, two hundred twenty-one million, one hundred twenty thousand, two hundred twenty-eight".