12605991779 has 2 divisors, whose sum is σ = 12605991780. Its totient is φ = 12605991778.

The previous prime is 12605991767. The next prime is 12605991857. The reversal of 12605991779 is 97719950621.

It is a weak prime.

It is an emirp because it is prime and its reverse (97719950621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12605991779 - 2²⁰ = 12604943203 is a prime.

It is a super-2 number, since 2×12605991779² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (12605991719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6302995889 + 6302995890.

It is an arithmetic number, because the mean of its divisors is an integer number (6302995890).

Almost surely, 2^12605991779 is an apocalyptic number.

12605991779 is a deficient number, since it is larger than the sum of its proper divisors (1).

12605991779 is an equidigital number, since it uses as much as digits as its factorization.

12605991779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2143260, while the sum is 56.

The spelling of 12605991779 in words is "twelve billion, six hundred five million, nine hundred ninety-one thousand, seven hundred seventy-nine".