256781473 has 6 divisors (see below), whose sum is σ = 278053494. Its totient is φ = 237028896.

The previous prime is 256781471. The next prime is 256781479. The reversal of 256781473 is 374187652.

256781473 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 44944 + 256736529 = 212^2 + 16023^2 .

It is not a de Polignac number, because 256781473 - 2¹ = 256781471 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256781471) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 759540 + ... + 759877.

It is an arithmetic number, because the mean of its divisors is an integer number (46342249).

Almost surely, 2^256781473 is an apocalyptic number.

It is an amenable number.

256781473 is a deficient number, since it is larger than the sum of its proper divisors (21272021).

256781473 is a wasteful number, since it uses less digits than its factorization.

256781473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1519443 (or 1519430 counting only the distinct ones).

The product of its digits is 282240, while the sum is 43.

The square root of 256781473 is about 16024.4024225554. The cubic root of 256781473 is about 635.6058639776.

The spelling of 256781473 in words is "two hundred fifty-six million, seven hundred eighty-one thousand, four hundred seventy-three".