1256559979 has 2 divisors, whose sum is σ = 1256559980. Its totient is φ = 1256559978.

The previous prime is 1256559961. The next prime is 1256560001. The reversal of 1256559979 is 9799556521.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1256559979 - 2¹¹ = 1256557931 is a prime.

It is not a weakly prime, because it can be changed into another prime (1256559929) 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, 628279989 + 628279990.

It is an arithmetic number, because the mean of its divisors is an integer number (628279990).

Almost surely, 2^1256559979 is an apocalyptic number.

1256559979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256559979 is an equidigital number, since it uses as much as digits as its factorization.

1256559979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7654500, while the sum is 58.

The square root of 1256559979 is about 35447.9897737516. The cubic root of 1256559979 is about 1079.0984643259.

The spelling of 1256559979 in words is "one billion, two hundred fifty-six million, five hundred fifty-nine thousand, nine hundred seventy-nine".