265666 has 4 divisors (see below), whose sum is σ = 398502. Its totient is φ = 132832.

The previous prime is 265621. The next prime is 265703. The reversal of 265666 is 666562.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 265225 + 441 = 515^2 + 21^2 .

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 265666.

It is an unprimeable 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, 66415 + ... + 66418.

2²⁶⁵⁶⁶⁶ is an apocalyptic number.

265666 is a deficient number, since it is larger than the sum of its proper divisors (132836).

265666 is a wasteful number, since it uses less digits than its factorization.

265666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132835.

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

The square root of 265666 is about 515.4279775100. The cubic root of 265666 is about 64.2853469703.

The spelling of 265666 in words is "two hundred sixty-five thousand, six hundred sixty-six".