1256633779 has 2 divisors, whose sum is σ = 1256633780. Its totient is φ = 1256633778.

The previous prime is 1256633731. The next prime is 1256633797. The reversal of 1256633779 is 9773366521.

Together with next prime (1256633797) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1256633779 - 2²¹ = 1254536627 is a prime.

It is a pancake number, because a pancake can be divided into 1256633779 parts by 50132 straight cuts.

It is not a weakly prime, because it can be changed into another prime (1256633179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628316889 + 628316890.

It is an arithmetic number, because the mean of its divisors is an integer number (628316890).

Almost surely, 2^1256633779 is an apocalyptic number.

1256633779 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256633779 is an equidigital number, since it uses as much as digits as its factorization.

1256633779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1428840, while the sum is 49.

The square root of 1256633779 is about 35449.0307201763. The cubic root of 1256633779 is about 1079.1195897023.

The spelling of 1256633779 in words is "one billion, two hundred fifty-six million, six hundred thirty-three thousand, seven hundred seventy-nine".