221129688 has 64 divisors (see below), whose sum is σ = 598348800. Its totient is φ = 67697280.

The previous prime is 221129663. The next prime is 221129707. The reversal of 221129688 is 886921122.

221129688 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64153 + ... + 67511.

It is an arithmetic number, because the mean of its divisors is an integer number (9349200).

Almost surely, 2^221129688 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 221129688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (299174400).

221129688 is an abundant number, since it is smaller than the sum of its proper divisors (377219112).

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

221129688 is a wasteful number, since it uses less digits than its factorization.

221129688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3592 (or 3588 counting only the distinct ones).

The product of its digits is 27648, while the sum is 39.

The square root of 221129688 is about 14870.4299870582. The cubic root of 221129688 is about 604.7125998742.

The spelling of 221129688 in words is "two hundred twenty-one million, one hundred twenty-nine thousand, six hundred eighty-eight".