256536666 has 16 divisors (see below), whose sum is σ = 570081600. Its totient is φ = 85512204.

The previous prime is 256536619. The next prime is 256536677. The reversal of 256536666 is 666635652.

256536666 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×256536666² = 131622122004791112, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2375286 + ... + 2375393.

It is an arithmetic number, because the mean of its divisors is an integer number (35630100).

Almost surely, 2^256536666 is an apocalyptic number.

256536666 is an abundant number, since it is smaller than the sum of its proper divisors (313544934).

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

256536666 is a wasteful number, since it uses less digits than its factorization.

256536666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4750690 (or 4750684 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 45.

The square root of 256536666 is about 16016.7620323210. The cubic root of 256536666 is about 635.4038111875.

The spelling of 256536666 in words is "two hundred fifty-six million, five hundred thirty-six thousand, six hundred sixty-six".