256765457 has 4 divisors (see below), whose sum is σ = 276516660. Its totient is φ = 237014256.

The previous prime is 256765451. The next prime is 256765469. The reversal of 256765457 is 754567652.

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

It can be written as a sum of positive squares in 2 ways, for example, as 112381201 + 144384256 = 10601^2 + 12016^2 .

It is a cyclic number.

It is not a de Polignac number, because 256765457 - 2⁴ = 256765441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256765451) 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, 9875582 + ... + 9875607.

It is an arithmetic number, because the mean of its divisors is an integer number (69129165).

Almost surely, 2^256765457 is an apocalyptic number.

It is an amenable number.

256765457 is a deficient number, since it is larger than the sum of its proper divisors (19751203).

256765457 is a wasteful number, since it uses less digits than its factorization.

256765457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19751202.

The product of its digits is 1764000, while the sum is 47.

The square root of 256765457 is about 16023.9026769386. The cubic root of 256765457 is about 635.5926490117.

The spelling of 256765457 in words is "two hundred fifty-six million, seven hundred sixty-five thousand, four hundred fifty-seven".