18791219779 has 2 divisors, whose sum is σ = 18791219780. Its totient is φ = 18791219778.

The previous prime is 18791219767. The next prime is 18791219827. The reversal of 18791219779 is 97791219781.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18791219779 is a prime.

It is not a weakly prime, because it can be changed into another prime (18791219729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9395609889 + 9395609890.

It is an arithmetic number, because the mean of its divisors is an integer number (9395609890).

Almost surely, 2^18791219779 is an apocalyptic number.

18791219779 is a deficient number, since it is larger than the sum of its proper divisors (1).

18791219779 is an equidigital number, since it uses as much as digits as its factorization.

18791219779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4000752, while the sum is 61.

The spelling of 18791219779 in words is "eighteen billion, seven hundred ninety-one million, two hundred nineteen thousand, seven hundred seventy-nine".