266535661 has 16 divisors (see below), whose sum is σ = 318357504. Its totient is φ = 218181744.

The previous prime is 266535649. The next prime is 266535671. The reversal of 266535661 is 166535662.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 266535661 - 2⁹ = 266535149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266535611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 174246 + ... + 175768.

It is an arithmetic number, because the mean of its divisors is an integer number (19897344).

Almost surely, 2^266535661 is an apocalyptic number.

It is an amenable number.

266535661 is a deficient number, since it is larger than the sum of its proper divisors (51821843).

266535661 is a wasteful number, since it uses less digits than its factorization.

266535661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2640.

The product of its digits is 194400, while the sum is 40.

The square root of 266535661 is about 16325.9199128257. The cubic root of 266535661 is about 643.5541686547.

Subtracting from 266535661 its reverse (166535662), we obtain a palindrome (99999999).

The spelling of 266535661 in words is "two hundred sixty-six million, five hundred thirty-five thousand, six hundred sixty-one".