1261275539 has 2 divisors, whose sum is σ = 1261275540. Its totient is φ = 1261275538.

The previous prime is 1261275473. The next prime is 1261275551. The reversal of 1261275539 is 9355721621.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1261275539 - 2⁸ = 1261275283 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 1261275496 and 1261275505.

It is not a weakly prime, because it can be changed into another prime (1261275599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630637769 + 630637770.

It is an arithmetic number, because the mean of its divisors is an integer number (630637770).

Almost surely, 2^1261275539 is an apocalyptic number.

1261275539 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261275539 is an equidigital number, since it uses as much as digits as its factorization.

1261275539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 113400, while the sum is 41.

The square root of 1261275539 is about 35514.4412739381. The cubic root of 1261275539 is about 1080.4466428223.

The spelling of 1261275539 in words is "one billion, two hundred sixty-one million, two hundred seventy-five thousand, five hundred thirty-nine".