1291356569 has 2 divisors, whose sum is σ = 1291356570. Its totient is φ = 1291356568.

The previous prime is 1291356497. The next prime is 1291356613. The reversal of 1291356569 is 9656531921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 675324169 + 616032400 = 25987^2 + 24820^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1291356569 is a prime.

It is a super-2 number, since 2×1291356569² = 3335203576598903522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1291356169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645678284 + 645678285.

It is an arithmetic number, because the mean of its divisors is an integer number (645678285).

Almost surely, 2^1291356569 is an apocalyptic number.

It is an amenable number.

1291356569 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291356569 is an equidigital number, since it uses as much as digits as its factorization.

1291356569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 437400, while the sum is 47.

The square root of 1291356569 is about 35935.4500319670. The cubic root of 1291356569 is about 1088.9686872894.

The spelling of 1291356569 in words is "one billion, two hundred ninety-one million, three hundred fifty-six thousand, five hundred sixty-nine".