221220220 has 48 divisors (see below), whose sum is σ = 502316640. Its totient is φ = 81351936.

The previous prime is 221220163. The next prime is 221220229. The reversal of 221220220 is 22022122.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a self number, because there is not a number n which added to its sum of digits gives 221220220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68359 + ... + 71521.

It is an arithmetic number, because the mean of its divisors is an integer number (10464930).

Almost surely, 2^221220220 is an apocalyptic number.

221220220 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 221220220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (251158320).

221220220 is an abundant number, since it is smaller than the sum of its proper divisors (281096420).

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

221220220 is a wasteful number, since it uses less digits than its factorization.

221220220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3454 (or 3452 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 221220220 is about 14873.4737032073. The cubic root of 221220220 is about 604.7951131001.

Adding to 221220220 its reverse (22022122), we get a palindrome (243242342).

The spelling of 221220220 in words is "two hundred twenty-one million, two hundred twenty thousand, two hundred twenty".