256457745 has 40 divisors (see below), whose sum is σ = 460919976. Its totient is φ = 136422144.

The previous prime is 256457723. The next prime is 256457771. The reversal of 256457745 is 547754652.

It can be written as a sum of positive squares in 4 ways, for example, as 16548624 + 239909121 = 4068^2 + 15489^2 .

It is not a de Polignac number, because 256457745 - 2²¹ = 254360593 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 256457745.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 247749 + ... + 248781.

Almost surely, 2^256457745 is an apocalyptic number.

It is an amenable number.

256457745 is a deficient number, since it is larger than the sum of its proper divisors (204462231).

256457745 is a wasteful number, since it uses less digits than its factorization.

256457745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663 (or 1654 counting only the distinct ones).

The product of its digits is 1176000, while the sum is 45.

The square root of 256457745 is about 16014.2981425974. The cubic root of 256457745 is about 635.3386459121.

The spelling of 256457745 in words is "two hundred fifty-six million, four hundred fifty-seven thousand, seven hundred forty-five".