12123818656921 has 16 divisors (see below), whose sum is σ = 12208096536768. Its totient is φ = 12039868684800.

The previous prime is 12123818656909. The next prime is 12123818656979. The reversal of 12123818656921 is 12965681832121.

It is a happy number.

12123818656921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 12123818656921 - 2²⁷ = 12123684439193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12123818656021) 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, 125214490 + ... + 125311276.

It is an arithmetic number, because the mean of its divisors is an integer number (763006033548).

Almost surely, 2^{12123818656921} is an apocalyptic number.

It is an amenable number.

12123818656921 is a deficient number, since it is larger than the sum of its proper divisors (84277879847).

12123818656921 is an equidigital number, since it uses as much as digits as its factorization.

12123818656921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98472.

The product of its digits is 2488320, while the sum is 55.

The spelling of 12123818656921 in words is "twelve trillion, one hundred twenty-three billion, eight hundred eighteen million, six hundred fifty-six thousand, nine hundred twenty-one".