1212166455779 has 2 divisors, whose sum is σ = 1212166455780. Its totient is φ = 1212166455778.

The previous prime is 1212166455761. The next prime is 1212166455859. The reversal of 1212166455779 is 9775546612121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1212166455779 - 2²⁰ = 1212165407203 is a prime.

It is not a weakly prime, because it can be changed into another prime (1212166451779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606083227889 + 606083227890.

It is an arithmetic number, because the mean of its divisors is an integer number (606083227890).

Almost surely, 2^{1212166455779} is an apocalyptic number.

1212166455779 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212166455779 is an equidigital number, since it uses as much as digits as its factorization.

1212166455779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6350400, while the sum is 56.

The spelling of 1212166455779 in words is "one trillion, two hundred twelve billion, one hundred sixty-six million, four hundred fifty-five thousand, seven hundred seventy-nine".