121121010021 has 32 divisors (see below), whose sum is σ = 177980664960. Its totient is φ = 72655232000.

The previous prime is 121121009983. The next prime is 121121010029. The reversal of 121121010021 is 120010121121.

It is a cyclic number.

It is not a de Polignac number, because 121121010021 - 2¹⁰ = 121121008997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121121009979 and 121121010006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121121010029) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16291321 + ... + 16298753.

It is an arithmetic number, because the mean of its divisors is an integer number (5561895780).

Almost surely, 2^121121010021 is an apocalyptic number.

121121010021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121121010021 is a deficient number, since it is larger than the sum of its proper divisors (56859654939).

121121010021 is a wasteful number, since it uses less digits than its factorization.

121121010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12437.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 121121010021 its reverse (120010121121), we get a palindrome (241131131142).

Subtracting from 121121010021 its reverse (120010121121), we obtain a square (1110888900 = 33330²).

The spelling of 121121010021 in words is "one hundred twenty-one billion, one hundred twenty-one million, ten thousand, twenty-one".