12345666779 has 4 divisors (see below), whose sum is σ = 12514785576. Its totient is φ = 12176547984.

The previous prime is 12345666769. The next prime is 12345666793. The reversal of 12345666779 is 97766654321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97766654321 = 7 ⋅13966664903.

It is a cyclic number.

It is not a de Polignac number, because 12345666779 - 2⁸ = 12345666523 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (12345666769) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84559289 + ... + 84559434.

It is an arithmetic number, because the mean of its divisors is an integer number (3128696394).

Almost surely, 2^12345666779 is an apocalyptic number.

12345666779 is a deficient number, since it is larger than the sum of its proper divisors (169118797).

12345666779 is an equidigital number, since it uses as much as digits as its factorization.

12345666779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169118796.

The product of its digits is 11430720, while the sum is 56.

The spelling of 12345666779 in words is "twelve billion, three hundred forty-five million, six hundred sixty-six thousand, seven hundred seventy-nine".