221201201220 has 96 divisors (see below), whose sum is σ = 639494123520. Its totient is φ = 57070673280.

The previous prime is 221201201219. The next prime is 221201201227. The reversal of 221201201220 is 22102102122.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 221201201220.

It is not an unprimeable number, because it can be changed into a prime (221201201227) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9621459 + ... + 9644421.

It is an arithmetic number, because the mean of its divisors is an integer number (6661397120).

Almost surely, 2^221201201220 is an apocalyptic number.

221201201220 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 221201201220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (319747061760).

221201201220 is an abundant number, since it is smaller than the sum of its proper divisors (418292922300).

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

221201201220 is a wasteful number, since it uses less digits than its factorization.

221201201220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28185 (or 28183 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 221201201220 its reverse (22102102122), we get a palindrome (243303303342).

The spelling of 221201201220 in words is "two hundred twenty-one billion, two hundred one million, two hundred one thousand, two hundred twenty".