256816506 has 8 divisors (see below), whose sum is σ = 513633024. Its totient is φ = 85605500.

The previous prime is 256816477. The next prime is 256816517. The reversal of 256816506 is 605618652.

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

256816506 is an admirable number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21401370 + ... + 21401381.

It is an arithmetic number, because the mean of its divisors is an integer number (64204128).

Almost surely, 2^256816506 is an apocalyptic number.

256816506 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256816506 is a wasteful number, since it uses less digits than its factorization.

256816506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42802756.

The product of its (nonzero) digits is 86400, while the sum is 39.

The square root of 256816506 is about 16025.4954993598. The cubic root of 256816506 is about 635.6347681497.

The spelling of 256816506 in words is "two hundred fifty-six million, eight hundred sixteen thousand, five hundred six".