256257506 has 8 divisors (see below), whose sum is σ = 384554844. Its totient is φ = 128072560.

The previous prime is 256257479. The next prime is 256257509. The reversal of 256257506 is 605752652.

It can be written as a sum of positive squares in 2 ways, for example, as 226653025 + 29604481 = 15055^2 + 5441^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 256257506.

It is not an unprimeable number, because it can be changed into a prime (256257509) 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, 22145 + ... + 31668.

Almost surely, 2^256257506 is an apocalyptic number.

256257506 is a deficient number, since it is larger than the sum of its proper divisors (128297338).

256257506 is a wasteful number, since it uses less digits than its factorization.

256257506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56196.

The product of its (nonzero) digits is 126000, while the sum is 38.

The square root of 256257506 is about 16008.0450399166. The cubic root of 256257506 is about 635.1732480348.

The spelling of 256257506 in words is "two hundred fifty-six million, two hundred fifty-seven thousand, five hundred six".