201221220021100 has 72 divisors (see below), whose sum is σ = 449671794163200. Its totient is φ = 78122703048000.

The previous prime is 201221220021071. The next prime is 201221220021149. The reversal of 201221220021100 is 1120022122102.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 215390176 + ... + 216322375.

It is an arithmetic number, because the mean of its divisors is an integer number (6245441585600).

Almost surely, 2^{201221220021100} is an apocalyptic number.

201221220021100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201221220021100 is an abundant number, since it is smaller than the sum of its proper divisors (248450574142100).

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

201221220021100 is a wasteful number, since it uses less digits than its factorization.

201221220021100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431712703 (or 431712696 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 201221220021100 its reverse (1120022122102), we get a palindrome (202341242143202).

The spelling of 201221220021100 in words is "two hundred one trillion, two hundred twenty-one billion, two hundred twenty million, twenty-one thousand, one hundred".