1256875091 has 4 divisors (see below), whose sum is σ = 1274092632. Its totient is φ = 1239657552.

The previous prime is 1256875033. The next prime is 1256875097. The reversal of 1256875091 is 1905786521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1905786521 = 5623 ⋅338927.

It is a cyclic number.

It is not a de Polignac number, because 1256875091 - 2⁶ = 1256875027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256875097) 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, 8608661 + ... + 8608806.

It is an arithmetic number, because the mean of its divisors is an integer number (318523158).

Almost surely, 2^1256875091 is an apocalyptic number.

1256875091 is a deficient number, since it is larger than the sum of its proper divisors (17217541).

1256875091 is an equidigital number, since it uses as much as digits as its factorization.

1256875091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17217540.

The product of its (nonzero) digits is 151200, while the sum is 44.

The square root of 1256875091 is about 35452.4342041559. The cubic root of 1256875091 is about 1079.1886599024.

The spelling of 1256875091 in words is "one billion, two hundred fifty-six million, eight hundred seventy-five thousand, ninety-one".