1256764331 has 2 divisors, whose sum is σ = 1256764332. Its totient is φ = 1256764330.

The previous prime is 1256764309. The next prime is 1256764343. The reversal of 1256764331 is 1334676521.

It is a strong prime.

It is an emirp because it is prime and its reverse (1334676521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1256764331 - 2³⁰ = 183022507 is a prime.

It is a super-3 number, since 3×1256764331³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (1256764381) 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, 628382165 + 628382166.

It is an arithmetic number, because the mean of its divisors is an integer number (628382166).

Almost surely, 2^1256764331 is an apocalyptic number.

1256764331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256764331 is an equidigital number, since it uses as much as digits as its factorization.

1256764331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 38.

The square root of 1256764331 is about 35450.8720767205. The cubic root of 1256764331 is about 1079.1569584103.

The spelling of 1256764331 in words is "one billion, two hundred fifty-six million, seven hundred sixty-four thousand, three hundred thirty-one".