201121200100021 has 16 divisors (see below), whose sum is σ = 215870615250048. Its totient is φ = 186696129830400.

The previous prime is 201121200100013. The next prime is 201121200100043. The reversal of 201121200100021 is 120001002121102.

It is a cyclic number.

It is not a de Polignac number, because 201121200100021 - 2³ = 201121200100013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201121200099974 and 201121200100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201121200101021) 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, 190477066 + ... + 191530036.

It is an arithmetic number, because the mean of its divisors is an integer number (13491913453128).

Almost surely, 2^{201121200100021} is an apocalyptic number.

It is an amenable number.

201121200100021 is a deficient number, since it is larger than the sum of its proper divisors (14749415150027).

201121200100021 is a wasteful number, since it uses less digits than its factorization.

201121200100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1206972.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 201121200100021 its reverse (120001002121102), we get a palindrome (321122202221123).

The spelling of 201121200100021 in words is "two hundred one trillion, one hundred twenty-one billion, two hundred million, one hundred thousand, twenty-one".