201221002121 has 4 divisors (see below), whose sum is σ = 211811581200. Its totient is φ = 190630423044.

The previous prime is 201221002069. The next prime is 201221002123. The reversal of 201221002121 is 121200122102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 201221002121 - 2³⁰ = 200147260297 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201221002096 and 201221002105.

It is not an unprimeable number, because it can be changed into a prime (201221002123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5295289511 + ... + 5295289548.

It is an arithmetic number, because the mean of its divisors is an integer number (52952895300).

Almost surely, 2^201221002121 is an apocalyptic number.

It is an amenable number.

201221002121 is a deficient number, since it is larger than the sum of its proper divisors (10590579079).

201221002121 is a wasteful number, since it uses less digits than its factorization.

201221002121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10590579078.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 201221002121 its reverse (121200122102), we get a palindrome (322421124223).

The spelling of 201221002121 in words is "two hundred one billion, two hundred twenty-one million, two thousand, one hundred twenty-one".