1266762689 has 2 divisors, whose sum is σ = 1266762690. Its totient is φ = 1266762688.

The previous prime is 1266762647. The next prime is 1266762719. The reversal of 1266762689 is 9862676621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 717329089 + 549433600 = 26783^2 + 23440^2 .

It is a cyclic number.

It is not a de Polignac number, because 1266762689 - 2¹² = 1266758593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1266762689.

It is not a weakly prime, because it can be changed into another prime (1266722689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633381344 + 633381345.

It is an arithmetic number, because the mean of its divisors is an integer number (633381345).

Almost surely, 2^1266762689 is an apocalyptic number.

It is an amenable number.

1266762689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266762689 is an equidigital number, since it uses as much as digits as its factorization.

1266762689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2612736, while the sum is 53.

The square root of 1266762689 is about 35591.6098118644. The cubic root of 1266762689 is about 1082.0111955204.

The spelling of 1266762689 in words is "one billion, two hundred sixty-six million, seven hundred sixty-two thousand, six hundred eighty-nine".