1256645659 has 2 divisors, whose sum is σ = 1256645660. Its totient is φ = 1256645658.

The previous prime is 1256645651. The next prime is 1256645681. The reversal of 1256645659 is 9565466521.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1256645659 - 2³ = 1256645651 is a prime.

It is not a weakly prime, because it can be changed into another prime (1256645651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628322829 + 628322830.

It is an arithmetic number, because the mean of its divisors is an integer number (628322830).

Almost surely, 2^1256645659 is an apocalyptic number.

1256645659 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256645659 is an equidigital number, since it uses as much as digits as its factorization.

1256645659 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944000, while the sum is 49.

The square root of 1256645659 is about 35449.1982843054. The cubic root of 1256645659 is about 1079.1229902953.

The spelling of 1256645659 in words is "one billion, two hundred fifty-six million, six hundred forty-five thousand, six hundred fifty-nine".