1291676257 has 2 divisors, whose sum is σ = 1291676258. Its totient is φ = 1291676256.

The previous prime is 1291676249. The next prime is 1291676263. The reversal of 1291676257 is 7526761921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1264229136 + 27447121 = 35556^2 + 5239^2 .

It is a cyclic number.

It is not a de Polignac number, because 1291676257 - 2³ = 1291676249 is a prime.

It is not a weakly prime, because it can be changed into another prime (1291670257) 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, 645838128 + 645838129.

It is an arithmetic number, because the mean of its divisors is an integer number (645838129).

Almost surely, 2^1291676257 is an apocalyptic number.

It is an amenable number.

1291676257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291676257 is an equidigital number, since it uses as much as digits as its factorization.

1291676257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 317520, while the sum is 46.

The square root of 1291676257 is about 35939.8978434831. The cubic root of 1291676257 is about 1089.0585415058.

It can be divided in two parts, 129167 and 6257, that added together give a square (135424 = 368²).

The spelling of 1291676257 in words is "one billion, two hundred ninety-one million, six hundred seventy-six thousand, two hundred fifty-seven".