221989924 has 12 divisors (see below), whose sum is σ = 418365724. Its totient is φ = 102456864.

The previous prime is 221989909. The next prime is 221989979. The reversal of 221989924 is 429989122.

It can be written as a sum of positive squares in 2 ways, for example, as 138815524 + 83174400 = 11782^2 + 9120^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2134467 + ... + 2134570.

Almost surely, 2^221989924 is an apocalyptic number.

It is an amenable number.

221989924 is a deficient number, since it is larger than the sum of its proper divisors (196375800).

221989924 is a wasteful number, since it uses less digits than its factorization.

221989924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4269054 (or 4269052 counting only the distinct ones).

The product of its digits is 186624, while the sum is 46.

The square root of 221989924 is about 14899.3262934939. The cubic root of 221989924 is about 605.4957337508.

The spelling of 221989924 in words is "two hundred twenty-one million, nine hundred eighty-nine thousand, nine hundred twenty-four".