12660784921 has 2 divisors, whose sum is σ = 12660784922. Its totient is φ = 12660784920.

The previous prime is 12660784909. The next prime is 12660784933. The reversal of 12660784921 is 12948706621.

It is a balanced prime because it is at equal distance from previous prime (12660784909) and next prime (12660784933).

It can be written as a sum of positive squares in only one way, i.e., 12284618896 + 376166025 = 110836^2 + 19395^2 .

It is a cyclic number.

It is not a de Polignac number, because 12660784921 - 2⁵ = 12660784889 is a prime.

It is not a weakly prime, because it can be changed into another prime (12660784321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6330392460 + 6330392461.

It is an arithmetic number, because the mean of its divisors is an integer number (6330392461).

Almost surely, 2^12660784921 is an apocalyptic number.

It is an amenable number.

12660784921 is a deficient number, since it is larger than the sum of its proper divisors (1).

12660784921 is an equidigital number, since it uses as much as digits as its factorization.

12660784921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 46.

The spelling of 12660784921 in words is "twelve billion, six hundred sixty million, seven hundred eighty-four thousand, nine hundred twenty-one".