1256478371 has 4 divisors (see below), whose sum is σ = 1261014672. Its totient is φ = 1251942072.

The previous prime is 1256478299. The next prime is 1256478373. The reversal of 1256478371 is 1738746521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1738746521 = 1777 ⋅978473.

It is a cyclic number.

It is not a de Polignac number, because 1256478371 - 2²⁶ = 1189369507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256478373) 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, 2267735 + ... + 2268288.

It is an arithmetic number, because the mean of its divisors is an integer number (315253668).

Almost surely, 2^1256478371 is an apocalyptic number.

1256478371 is a deficient number, since it is larger than the sum of its proper divisors (4536301).

1256478371 is an equidigital number, since it uses as much as digits as its factorization.

1256478371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4536300.

The product of its digits is 282240, while the sum is 44.

The square root of 1256478371 is about 35446.8386601683. The cubic root of 1256478371 is about 1079.0751029330.

The spelling of 1256478371 in words is "one billion, two hundred fifty-six million, four hundred seventy-eight thousand, three hundred seventy-one".