256447566 has 16 divisors (see below), whose sum is σ = 569883600. Its totient is φ = 85482504.

The previous prime is 256447561. The next prime is 256447591. The reversal of 256447566 is 665744652.

256447566 is a `hidden beast` number, since 25 + 64 + 4 + 7 + 566 = 666.

It is a Curzon number.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 2374461 + ... + 2374568.

It is an arithmetic number, because the mean of its divisors is an integer number (35617725).

Almost surely, 2^256447566 is an apocalyptic number.

256447566 is an abundant number, since it is smaller than the sum of its proper divisors (313436034).

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

256447566 is a wasteful number, since it uses less digits than its factorization.

256447566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4749040 (or 4749034 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 45.

The square root of 256447566 is about 16013.9803296994. The cubic root of 256447566 is about 635.3302401120.

The spelling of 256447566 in words is "two hundred fifty-six million, four hundred forty-seven thousand, five hundred sixty-six".