1256009 has 2 divisors, whose sum is σ = 1256010. Its totient is φ = 1256008.

The previous prime is 1255997. The next prime is 1256023. The reversal of 1256009 is 9006521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1006009 + 250000 = 1003^2 + 500^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256009 - 2⁴ = 1255993 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1256029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628004 + 628005.

It is an arithmetic number, because the mean of its divisors is an integer number (628005).

2^1256009 is an apocalyptic number.

It is an amenable number.

1256009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256009 is an equidigital number, since it uses as much as digits as its factorization.

1256009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 1256009 is about 1120.7180733797. The cubic root of 1256009 is about 107.8940719497.

The spelling of 1256009 in words is "one million, two hundred fifty-six thousand, nine".