221000220 has 144 divisors (see below), whose sum is σ = 784143360. Its totient is φ = 49327488.

The previous prime is 221000141. The next prime is 221000243. The reversal of 221000220 is 22000122.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 52141 + ... + 56219.

It is an arithmetic number, because the mean of its divisors is an integer number (5445440).

Almost surely, 2^221000220 is an apocalyptic number.

221000220 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 221000220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (392071680).

221000220 is an abundant number, since it is smaller than the sum of its proper divisors (563143140).

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

221000220 is a wasteful number, since it uses less digits than its factorization.

221000220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4144 (or 4139 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 221000220 is about 14866.0761467174. The cubic root of 221000220 is about 604.5945602207.

Adding to 221000220 its reverse (22000122), we get a palindrome (243000342).

The spelling of 221000220 in words is "two hundred twenty-one million, two hundred twenty", and thus it is an aban number.