12121010921 has 2 divisors, whose sum is σ = 12121010922. Its totient is φ = 12121010920.

The previous prime is 12121010911. The next prime is 12121010959. The reversal of 12121010921 is 12901012121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9247514896 + 2873496025 = 96164^2 + 53605^2 .

It is a cyclic number.

It is not a de Polignac number, because 12121010921 - 2¹⁰ = 12121009897 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 12121010893 and 12121010902.

It is not a weakly prime, because it can be changed into another prime (12121010911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6060505460 + 6060505461.

It is an arithmetic number, because the mean of its divisors is an integer number (6060505461).

Almost surely, 2^12121010921 is an apocalyptic number.

It is an amenable number.

12121010921 is a deficient number, since it is larger than the sum of its proper divisors (1).

12121010921 is an equidigital number, since it uses as much as digits as its factorization.

12121010921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 12121010921 in words is "twelve billion, one hundred twenty-one million, ten thousand, nine hundred twenty-one".