12390194891 has 2 divisors, whose sum is σ = 12390194892. Its totient is φ = 12390194890.

The previous prime is 12390194857. The next prime is 12390194911. The reversal of 12390194891 is 19849109321.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12390194891 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (12390194851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6195097445 + 6195097446.

It is an arithmetic number, because the mean of its divisors is an integer number (6195097446).

Almost surely, 2^12390194891 is an apocalyptic number.

12390194891 is a deficient number, since it is larger than the sum of its proper divisors (1).

12390194891 is an equidigital number, since it uses as much as digits as its factorization.

12390194891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139968, while the sum is 47.

The spelling of 12390194891 in words is "twelve billion, three hundred ninety million, one hundred ninety-four thousand, eight hundred ninety-one".