256447563 has 4 divisors (see below), whose sum is σ = 341930088. Its totient is φ = 170965040.

The previous prime is 256447561. The next prime is 256447591. The reversal of 256447563 is 365744652.

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

It is a cyclic number.

It is not a de Polignac number, because 256447563 - 2¹ = 256447561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256447561) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 42741258 + ... + 42741263.

It is an arithmetic number, because the mean of its divisors is an integer number (85482522).

Almost surely, 2^256447563 is an apocalyptic number.

256447563 is a deficient number, since it is larger than the sum of its proper divisors (85482525).

256447563 is an equidigital number, since it uses as much as digits as its factorization.

256447563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85482524.

The product of its digits is 604800, while the sum is 42.

The square root of 256447563 is about 16013.9802360313. The cubic root of 256447563 is about 635.3302376346.

The spelling of 256447563 in words is "two hundred fifty-six million, four hundred forty-seven thousand, five hundred sixty-three".