201221312121 has 48 divisors (see below), whose sum is σ = 301881740160. Its totient is φ = 129068640000.

The previous prime is 201221312101. The next prime is 201221312129. The reversal of 201221312121 is 121213122102.

201221312121 is a `hidden beast` number, since 201 + 221 + 31 + 212 + 1 = 666.

It is not a de Polignac number, because 201221312121 - 2²² = 201217117817 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 201221312094 and 201221312103.

It is not an unprimeable number, because it can be changed into a prime (201221312129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7731951 + ... + 7757931.

It is an arithmetic number, because the mean of its divisors is an integer number (6289202920).

Almost surely, 2^201221312121 is an apocalyptic number.

It is an amenable number.

201221312121 is a deficient number, since it is larger than the sum of its proper divisors (100660428039).

201221312121 is a wasteful number, since it uses less digits than its factorization.

201221312121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26318 (or 26315 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 201221312121 its reverse (121213122102), we get a palindrome (322434434223).

The spelling of 201221312121 in words is "two hundred one billion, two hundred twenty-one million, three hundred twelve thousand, one hundred twenty-one".