201221100221021 has 16 divisors (see below), whose sum is σ = 213802982429760. Its totient is φ = 188838543640320.

The previous prime is 201221100220967. The next prime is 201221100221123. The reversal of 201221100221021 is 120122001122102.

It is a cyclic number.

It is not a de Polignac number, because 201221100221021 - 2²⁶ = 201221033112157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221100221621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34405811 + ... + 39827151.

It is an arithmetic number, because the mean of its divisors is an integer number (13362686401860).

Almost surely, 2^{201221100221021} is an apocalyptic number.

It is an amenable number.

201221100221021 is a deficient number, since it is larger than the sum of its proper divisors (12581882208739).

201221100221021 is a wasteful number, since it uses less digits than its factorization.

201221100221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5439724.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 201221100221021 its reverse (120122001122102), we get a palindrome (321343101343123).

The spelling of 201221100221021 in words is "two hundred one trillion, two hundred twenty-one billion, one hundred million, two hundred twenty-one thousand, twenty-one".