12394538521 has 2 divisors, whose sum is σ = 12394538522. Its totient is φ = 12394538520.

The previous prime is 12394538509. The next prime is 12394538537. The reversal of 12394538521 is 12583549321.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9439094025 + 2955444496 = 97155^2 + 54364^2 .

It is a cyclic number.

It is not a de Polignac number, because 12394538521 - 2⁷ = 12394538393 is a prime.

It is not a weakly prime, because it can be changed into another prime (12394538561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6197269260 + 6197269261.

It is an arithmetic number, because the mean of its divisors is an integer number (6197269261).

Almost surely, 2^12394538521 is an apocalyptic number.

It is an amenable number.

12394538521 is a deficient number, since it is larger than the sum of its proper divisors (1).

12394538521 is an equidigital number, since it uses as much as digits as its factorization.

12394538521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 259200, while the sum is 43.

The spelling of 12394538521 in words is "twelve billion, three hundred ninety-four million, five hundred thirty-eight thousand, five hundred twenty-one".