201221012121021 has 12 divisors (see below), whose sum is σ = 290652796014880. Its totient is φ = 134147238513480.

The previous prime is 201221012120993. The next prime is 201221012121029. The reversal of 201221012121021 is 120121210122102.

201221012121021 is a `hidden beast` number, since 201 + 2 + 210 + 1 + 21 + 210 + 21 = 666.

It is not a de Polignac number, because 201221012121021 - 2¹⁸ = 201221011858877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201221012120985 and 201221012121003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221012121029) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4929006 + ... + 20657616.

Almost surely, 2^{201221012121021} is an apocalyptic number.

It is an amenable number.

201221012121021 is a deficient number, since it is larger than the sum of its proper divisors (89431783893859).

201221012121021 is a wasteful number, since it uses less digits than its factorization.

201221012121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17150096 (or 17150093 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 201221012121021 its reverse (120121210122102), we get a palindrome (321342222243123).

The spelling of 201221012121021 in words is "two hundred one trillion, two hundred twenty-one billion, twelve million, one hundred twenty-one thousand, twenty-one".