266656 has 24 divisors (see below), whose sum is σ = 566244. Its totient is φ = 122880.

The previous prime is 266647. The next prime is 266663. The reversal of 266656 is 656662.

It can be written as a sum of positive squares in 2 ways, for example, as 266256 + 400 = 516^2 + 20^2 .

It is a super-2 number, since 2×266656² = 142210844672, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96 + ... + 736.

2²⁶⁶⁶⁵⁶ is an apocalyptic number.

266656 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 266656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (283122).

266656 is an abundant number, since it is smaller than the sum of its proper divisors (299588).

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

266656 is a wasteful number, since it uses less digits than its factorization.

266656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664 (or 656 counting only the distinct ones).

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

The square root of 266656 is about 516.3874514355. The cubic root of 266656 is about 64.3651007495.

It can be divided in two parts, 26 and 6656, that multiplied together give a square (173056 = 416²).

The spelling of 266656 in words is "two hundred sixty-six thousand, six hundred fifty-six".