221709222 has 72 divisors (see below), whose sum is σ = 572520312. Its totient is φ = 61790400.

The previous prime is 221709211. The next prime is 221709239. The reversal of 221709222 is 222907122.

221709222 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 33097 + ... + 39227.

It is an arithmetic number, because the mean of its divisors is an integer number (7951671).

Almost surely, 2^221709222 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221709222, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286260156).

221709222 is an abundant number, since it is smaller than the sum of its proper divisors (350811090).

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

221709222 is a wasteful number, since it uses less digits than its factorization.

221709222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6194 (or 6184 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 221709222 is about 14889.9033576447. The cubic root of 221709222 is about 605.2404135251.

The spelling of 221709222 in words is "two hundred twenty-one million, seven hundred nine thousand, two hundred twenty-two".