121221020021 has 16 divisors (see below), whose sum is σ = 125205575040. Its totient is φ = 117308568000.

The previous prime is 121221020009. The next prime is 121221020051. The reversal of 121221020021 is 120020122121.

It is a cyclic number.

It is not a de Polignac number, because 121221020021 - 2¹⁸ = 121220757877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121221019978 and 121221020005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221020051) 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, 1325975 + ... + 1414443.

It is an arithmetic number, because the mean of its divisors is an integer number (7825348440).

Almost surely, 2^121221020021 is an apocalyptic number.

It is an amenable number.

121221020021 is a deficient number, since it is larger than the sum of its proper divisors (3984555019).

121221020021 is a wasteful number, since it uses less digits than its factorization.

121221020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88876.

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

Adding to 121221020021 its reverse (120020122121), we get a palindrome (241241142142).

The spelling of 121221020021 in words is "one hundred twenty-one billion, two hundred twenty-one million, twenty thousand, twenty-one".