1256426609 has 2 divisors, whose sum is σ = 1256426610. Its totient is φ = 1256426608.

The previous prime is 1256426593. The next prime is 1256426659. The reversal of 1256426609 is 9066246521.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1204298209 + 52128400 = 34703^2 + 7220^2 .

It is a cyclic number.

It is not a de Polignac number, because 1256426609 - 2⁴ = 1256426593 is a prime.

It is not a weakly prime, because it can be changed into another prime (1256426659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628213304 + 628213305.

It is an arithmetic number, because the mean of its divisors is an integer number (628213305).

Almost surely, 2^1256426609 is an apocalyptic number.

It is an amenable number.

1256426609 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256426609 is an equidigital number, since it uses as much as digits as its factorization.

1256426609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 41.

The square root of 1256426609 is about 35446.1085170150. The cubic root of 1256426609 is about 1079.0602848367.

The spelling of 1256426609 in words is "one billion, two hundred fifty-six million, four hundred twenty-six thousand, six hundred nine".