666256 has 10 divisors (see below), whose sum is σ = 1290902. Its totient is φ = 333120.

The previous prime is 666233. The next prime is 666269. The reversal of 666256 is 652666.

It can be written as a sum of positive squares in only one way, i.e., 665856 + 400 = 816^2 + 20^2 .

It is an unprimeable number.

666256 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20805 + ... + 20836.

2⁶⁶⁶²⁵⁶ is an apocalyptic number.

It is an amenable number.

666256 is a deficient number, since it is larger than the sum of its proper divisors (624646).

666256 is a wasteful number, since it uses less digits than its factorization.

666256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41649 (or 41643 counting only the distinct ones).

The product of its digits is 12960, while the sum is 31.

The square root of 666256 is about 816.2450612408. The cubic root of 666256 is about 87.3401052703.

The spelling of 666256 in words is "six hundred sixty-six thousand, two hundred fifty-six".