121002002100021 has 24 divisors (see below), whose sum is σ = 195868127976640. Its totient is φ = 65076707008512.

The previous prime is 121002002100017. The next prime is 121002002100079. The reversal of 121002002100021 is 120001200200121.

It is not a de Polignac number, because 121002002100021 - 2² = 121002002100017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121002002100011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9968852236 + ... + 9968864373.

Almost surely, 2^{121002002100021} is an apocalyptic number.

It is an amenable number.

121002002100021 is a deficient number, since it is larger than the sum of its proper divisors (74866125876619).

121002002100021 is a wasteful number, since it uses less digits than its factorization.

121002002100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19937716653 (or 19937716636 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 121002002100021 its reverse (120001200200121), we get a palindrome (241003202300142).

The spelling of 121002002100021 in words is "one hundred twenty-one trillion, two billion, two million, one hundred thousand, twenty-one".