256646646 has 12 divisors (see below), whose sum is σ = 556067772. Its totient is φ = 85548876.

The previous prime is 256646633. The next prime is 256646651. The reversal of 256646646 is 646646652.

256646646 is a `hidden beast` number, since 2 + 566 + 46 + 6 + 46 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7129056 + ... + 7129091.

It is an arithmetic number, because the mean of its divisors is an integer number (46338981).

Almost surely, 2^256646646 is an apocalyptic number.

256646646 is an abundant number, since it is smaller than the sum of its proper divisors (299421126).

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

256646646 is a wasteful number, since it uses less digits than its factorization.

256646646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14258155 (or 14258152 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 45.

The square root of 256646646 is about 16020.1949426341. The cubic root of 256646646 is about 635.4945996744.

The spelling of 256646646 in words is "two hundred fifty-six million, six hundred forty-six thousand, six hundred forty-six".