221998688 has 36 divisors (see below), whose sum is σ = 451675980. Its totient is φ = 107403840.

The previous prime is 221998639. The next prime is 221998787. The reversal of 221998688 is 886899122.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 27143 + ... + 34361.

It is an arithmetic number, because the mean of its divisors is an integer number (12546555).

Almost surely, 2^221998688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221998688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225837990).

221998688 is an abundant number, since it is smaller than the sum of its proper divisors (229677292).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221998688 is an equidigital number, since it uses as much as digits as its factorization.

221998688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7291 (or 7252 counting only the distinct ones).

The product of its digits is 995328, while the sum is 53.

The square root of 221998688 is about 14899.6203978491. The cubic root of 221998688 is about 605.5037018223.

The spelling of 221998688 in words is "two hundred twenty-one million, nine hundred ninety-eight thousand, six hundred eighty-eight".