12665434321 has 2 divisors, whose sum is σ = 12665434322. Its totient is φ = 12665434320.

The previous prime is 12665434297. The next prime is 12665434351. The reversal of 12665434321 is 12343456621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8918158096 + 3747276225 = 94436^2 + 61215^2 .

It is a cyclic number.

It is not a de Polignac number, because 12665434321 - 2⁵ = 12665434289 is a prime.

It is not a weakly prime, because it can be changed into another prime (12665434351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6332717160 + 6332717161.

It is an arithmetic number, because the mean of its divisors is an integer number (6332717161).

Almost surely, 2^12665434321 is an apocalyptic number.

It is an amenable number.

12665434321 is a deficient number, since it is larger than the sum of its proper divisors (1).

12665434321 is an equidigital number, since it uses as much as digits as its factorization.

12665434321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 37.

The spelling of 12665434321 in words is "twelve billion, six hundred sixty-five million, four hundred thirty-four thousand, three hundred twenty-one".