221100201220 has 24 divisors (see below), whose sum is σ = 465504039000. Its totient is φ = 88212724992.

The previous prime is 221100201199. The next prime is 221100201227. The reversal of 221100201220 is 22102001122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 15087700224 + 206012500996 = 122832^2 + 453886^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 221100201220.

It is not an unprimeable number, because it can be changed into a prime (221100201227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14201745 + ... + 14217304.

It is an arithmetic number, because the mean of its divisors is an integer number (19396001625).

Almost surely, 2^221100201220 is an apocalyptic number.

221100201220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221100201220 is an abundant number, since it is smaller than the sum of its proper divisors (244403837780).

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

221100201220 is a wasteful number, since it uses less digits than its factorization.

221100201220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28419447 (or 28419445 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 221100201220 its reverse (22102001122), we get a palindrome (243202202342).

The spelling of 221100201220 in words is "two hundred twenty-one billion, one hundred million, two hundred one thousand, two hundred twenty".