221989999 has 16 divisors (see below), whose sum is σ = 277286400. Its totient is φ = 172654560.

The previous prime is 221989987. The next prime is 221990003. The reversal of 221989999 is 999989122.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 221989999 - 2⁷ = 221989871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221989909) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 43717 + ... + 48529.

It is an arithmetic number, because the mean of its divisors is an integer number (17330400).

Almost surely, 2^221989999 is an apocalyptic number.

221989999 is a deficient number, since it is larger than the sum of its proper divisors (55296401).

221989999 is a wasteful number, since it uses less digits than its factorization.

221989999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5430.

The product of its digits is 1889568, while the sum is 58.

The square root of 221989999 is about 14899.3288103861. The cubic root of 221989999 is about 605.4958019403.

The spelling of 221989999 in words is "two hundred twenty-one million, nine hundred eighty-nine thousand, nine hundred ninety-nine".