1256763257 has 4 divisors (see below), whose sum is σ = 1268508816. Its totient is φ = 1245017700.

The previous prime is 1256763251. The next prime is 1256763259. The reversal of 1256763257 is 7523676521.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7523676521 = 35899 ⋅209579.

It is a cyclic number.

It is not a de Polignac number, because 1256763257 - 2¹⁴ = 1256746873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256763251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5872619 + ... + 5872832.

It is an arithmetic number, because the mean of its divisors is an integer number (317127204).

Almost surely, 2^1256763257 is an apocalyptic number.

It is an amenable number.

1256763257 is a deficient number, since it is larger than the sum of its proper divisors (11745559).

1256763257 is a wasteful number, since it uses less digits than its factorization.

1256763257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11745558.

The product of its digits is 529200, while the sum is 44.

The square root of 1256763257 is about 35450.8569289940. The cubic root of 1256763257 is about 1079.1566510032.

The spelling of 1256763257 in words is "one billion, two hundred fifty-six million, seven hundred sixty-three thousand, two hundred fifty-seven".