256040506 has 8 divisors (see below), whose sum is σ = 386010900. Its totient is φ = 127370208.

The previous prime is 256040503. The next prime is 256040513. The reversal of 256040506 is 605040652.

It can be written as a sum of positive squares in 2 ways, for example, as 216237025 + 39803481 = 14705^2 + 6309^2 .

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

It is not an unprimeable number, because it can be changed into a prime (256040503) 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, 324531 + ... + 325318.

Almost surely, 2^256040506 is an apocalyptic number.

256040506 is a deficient number, since it is larger than the sum of its proper divisors (129970394).

256040506 is a wasteful number, since it uses less digits than its factorization.

256040506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650048.

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 256040506 is about 16001.2657624327. The cubic root of 256040506 is about 634.9939082227.

The spelling of 256040506 in words is "two hundred fifty-six million, forty thousand, five hundred six".