1266665993 has 2 divisors, whose sum is σ = 1266665994. Its totient is φ = 1266665992.

The previous prime is 1266665977. The next prime is 1266666041. The reversal of 1266665993 is 3995666621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1265438329 + 1227664 = 35573^2 + 1108^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266665993 - 2⁴ = 1266665977 is a prime.

It is not a weakly prime, because it can be changed into another prime (1266665923) 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, 633332996 + 633332997.

It is an arithmetic number, because the mean of its divisors is an integer number (633332997).

Almost surely, 2^1266665993 is an apocalyptic number.

It is an amenable number.

1266665993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266665993 is an equidigital number, since it uses as much as digits as its factorization.

1266665993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3149280, while the sum is 53.

The square root of 1266665993 is about 35590.2513759035. The cubic root of 1266665993 is about 1081.9836637083.

The spelling of 1266665993 in words is "one billion, two hundred sixty-six million, six hundred sixty-five thousand, nine hundred ninety-three".