221668522 has 8 divisors (see below), whose sum is σ = 332669700. Its totient is φ = 110778624.

The previous prime is 221668519. The next prime is 221668529. The reversal of 221668522 is 225866122.

221668522 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 184932801 + 36735721 = 13599^2 + 6061^2 .

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

It is not an unprimeable number, because it can be changed into a prime (221668529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22647 + ... + 30922.

Almost surely, 2^221668522 is an apocalyptic number.

221668522 is a deficient number, since it is larger than the sum of its proper divisors (111001178).

221668522 is a wasteful number, since it uses less digits than its factorization.

221668522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55640.

The product of its digits is 23040, while the sum is 34.

The square root of 221668522 is about 14888.5365969930. The cubic root of 221668522 is about 605.2033758350.

The spelling of 221668522 in words is "two hundred twenty-one million, six hundred sixty-eight thousand, five hundred twenty-two".