221722920 has 96 divisors (see below), whose sum is σ = 747321120. Its totient is φ = 59123520.

The previous prime is 221722889. The next prime is 221722927. The reversal of 221722920 is 29227122.

221722920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221722920² = 98322106506652800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (221722927) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1686 + ... + 21125.

It is an arithmetic number, because the mean of its divisors is an integer number (7784595).

Almost surely, 2^221722920 is an apocalyptic number.

221722920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221722920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (373660560).

221722920 is an abundant number, since it is smaller than the sum of its proper divisors (525598200).

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

221722920 is a wasteful number, since it uses less digits than its factorization.

221722920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22837 (or 22821 counting only the distinct ones).

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

The square root of 221722920 is about 14890.3633266620. The cubic root of 221722920 is about 605.2528779178.

The spelling of 221722920 in words is "two hundred twenty-one million, seven hundred twenty-two thousand, nine hundred twenty".