1216765577 has 2 divisors, whose sum is σ = 1216765578. Its totient is φ = 1216765576.

The previous prime is 1216765549. The next prime is 1216765601. The reversal of 1216765577 is 7755676121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 623550841 + 593214736 = 24971^2 + 24356^2 .

It is a cyclic number.

It is not a de Polignac number, because 1216765577 - 2⁸ = 1216765321 is a prime.

It is not a weakly prime, because it can be changed into another prime (1216765877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608382788 + 608382789.

It is an arithmetic number, because the mean of its divisors is an integer number (608382789).

Almost surely, 2^1216765577 is an apocalyptic number.

It is an amenable number.

1216765577 is a deficient number, since it is larger than the sum of its proper divisors (1).

1216765577 is an equidigital number, since it uses as much as digits as its factorization.

1216765577 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 617400, while the sum is 47.

The square root of 1216765577 is about 34882.1670341738. The cubic root of 1216765577 is about 1067.5846110632.

The spelling of 1216765577 in words is "one billion, two hundred sixteen million, seven hundred sixty-five thousand, five hundred seventy-seven".