1256609 has 4 divisors (see below), whose sum is σ = 1287300. Its totient is φ = 1225920.

The previous prime is 1256597. The next prime is 1256611. The reversal of 1256609 is 9066521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9066521 = 1489 ⋅6089.

It can be written as a sum of positive squares in 2 ways, for example, as 40000 + 1216609 = 200^2 + 1103^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1256609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15284 + ... + 15365.

It is an arithmetic number, because the mean of its divisors is an integer number (321825).

2^1256609 is an apocalyptic number.

It is an amenable number.

1256609 is a deficient number, since it is larger than the sum of its proper divisors (30691).

1256609 is an equidigital number, since it uses as much as digits as its factorization.

1256609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30690.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 1256609 is about 1120.9857269386. The cubic root of 1256609 is about 107.9112496763.

The spelling of 1256609 in words is "one million, two hundred fifty-six thousand, six hundred nine".