12261779899 has 2 divisors, whose sum is σ = 12261779900. Its totient is φ = 12261779898.

The previous prime is 12261779879. The next prime is 12261779953. The reversal of 12261779899 is 99897716221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12261779899 - 2⁵ = 12261779867 is a prime.

It is not a weakly prime, because it can be changed into another prime (12261779879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6130889949 + 6130889950.

It is an arithmetic number, because the mean of its divisors is an integer number (6130889950).

Almost surely, 2^12261779899 is an apocalyptic number.

12261779899 is a deficient number, since it is larger than the sum of its proper divisors (1).

12261779899 is an equidigital number, since it uses as much as digits as its factorization.

12261779899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6858432, while the sum is 61.

The spelling of 12261779899 in words is "twelve billion, two hundred sixty-one million, seven hundred seventy-nine thousand, eight hundred ninety-nine".