12191779 has 2 divisors, whose sum is σ = 12191780. Its totient is φ = 12191778.

The previous prime is 12191741. The next prime is 12191783. The reversal of 12191779 is 97719121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12191779 - 2⁷ = 12191651 is a prime.

It is not a weakly prime, because it can be changed into another prime (12191279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6095889 + 6095890.

It is an arithmetic number, because the mean of its divisors is an integer number (6095890).

Almost surely, 2^12191779 is an apocalyptic number.

12191779 is a deficient number, since it is larger than the sum of its proper divisors (1).

12191779 is an equidigital number, since it uses as much as digits as its factorization.

12191779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7938, while the sum is 37.

The square root of 12191779 is about 3491.6728082683. The cubic root of 12191779 is about 230.1560314907.

The spelling of 12191779 in words is "twelve million, one hundred ninety-one thousand, seven hundred seventy-nine".