1291009 has 2 divisors, whose sum is σ = 1291010. Its totient is φ = 1291008.

The previous prime is 1291007. The next prime is 1291019. The reversal of 1291009 is 9001921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1166400 + 124609 = 1080^2 + 353^2 .

It is a cyclic number.

It is not a de Polignac number, because 1291009 - 2¹ = 1291007 is a prime.

Together with 1291007, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645504 + 645505.

It is an arithmetic number, because the mean of its divisors is an integer number (645505).

2^1291009 is an apocalyptic number.

It is an amenable number.

1291009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291009 is an equidigital number, since it uses as much as digits as its factorization.

1291009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 1291009 is about 1136.2257698187. The cubic root of 1291009 is about 108.8870979775.

The spelling of 1291009 in words is "one million, two hundred ninety-one thousand, nine".