1256645667 has 16 divisors (see below), whose sum is σ = 1731704832. Its totient is φ = 809741760.

The previous prime is 1256645659. The next prime is 1256645681. The reversal of 1256645667 is 7665466521.

It is not a de Polignac number, because 1256645667 - 2³ = 1256645659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1256645267) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71818 + ... + 87584.

It is an arithmetic number, because the mean of its divisors is an integer number (108231552).

Almost surely, 2^1256645667 is an apocalyptic number.

1256645667 is a deficient number, since it is larger than the sum of its proper divisors (475059165).

1256645667 is a wasteful number, since it uses less digits than its factorization.

1256645667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16658.

The product of its digits is 1814400, while the sum is 48.

The square root of 1256645667 is about 35449.1983971429. The cubic root of 1256645667 is about 1079.1229925853.

The spelling of 1256645667 in words is "one billion, two hundred fifty-six million, six hundred forty-five thousand, six hundred sixty-seven".