266661 has 6 divisors (see below), whose sum is σ = 385190. Its totient is φ = 177768.

The previous prime is 266647. The next prime is 266663. The reversal of 266661 is 166662.

It can be written as a sum of positive squares in only one way, i.e., 260100 + 6561 = 510^2 + 81^2 .

It is not a de Polignac number, because 266661 - 2¹³ = 258469 is a prime.

It is a super-2 number, since 2×266661² = 142216177842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266663) by changing a digit.

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 in 5 ways as a sum of consecutive naturals, for example, 14806 + ... + 14823.

2²⁶⁶⁶⁶¹ is an apocalyptic number.

It is an amenable number.

266661 is a deficient number, since it is larger than the sum of its proper divisors (118529).

266661 is a wasteful number, since it uses less digits than its factorization.

266661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29635 (or 29632 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 266661 is about 516.3922927388. The cubic root of 266661 is about 64.3655030449.

Subtracting from 266661 its reverse (166662), we obtain a palindrome (99999).

The spelling of 266661 in words is "two hundred sixty-six thousand, six hundred sixty-one".