1266539399 has 2 divisors, whose sum is σ = 1266539400. Its totient is φ = 1266539398.

The previous prime is 1266539383. The next prime is 1266539431. The reversal of 1266539399 is 9939356621.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1266539399 - 2⁴ = 1266539383 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1266539399.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1266539299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633269699 + 633269700.

It is an arithmetic number, because the mean of its divisors is an integer number (633269700).

Almost surely, 2^1266539399 is an apocalyptic number.

1266539399 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266539399 is an equidigital number, since it uses as much as digits as its factorization.

1266539399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2361960, while the sum is 53.

The square root of 1266539399 is about 35588.4728388280. The cubic root of 1266539399 is about 1081.9476170567.

The spelling of 1266539399 in words is "one billion, two hundred sixty-six million, five hundred thirty-nine thousand, three hundred ninety-nine".