256871771 has 4 divisors (see below), whose sum is σ = 276631152. Its totient is φ = 237112392.

The previous prime is 256871759. The next prime is 256871801. The reversal of 256871771 is 177178652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256871771 - 2⁶ = 256871707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256871701) 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, 9879671 + ... + 9879696.

It is an arithmetic number, because the mean of its divisors is an integer number (69157788).

Almost surely, 2^256871771 is an apocalyptic number.

256871771 is a deficient number, since it is larger than the sum of its proper divisors (19759381).

256871771 is a wasteful number, since it uses less digits than its factorization.

256871771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19759380.

The product of its digits is 164640, while the sum is 44.

The square root of 256871771 is about 16027.2196902644. The cubic root of 256871771 is about 635.6803595027.

The spelling of 256871771 in words is "two hundred fifty-six million, eight hundred seventy-one thousand, seven hundred seventy-one".