266666666657 has 4 divisors (see below), whose sum is σ = 266819837076. Its totient is φ = 266513496240.

The previous prime is 266666666611. The next prime is 266666666663. The reversal of 266666666657 is 756666666662.

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

It can be written as a sum of positive squares in 2 ways, for example, as 106377736336 + 160288930321 = 326156^2 + 400361^2 .

It is a cyclic number.

It is not a de Polignac number, because 266666666657 - 2¹⁶ = 266666601121 is a prime.

It is a super-2 number, since 2×266666666657² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (266666666257) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76582598 + ... + 76586079.

It is an arithmetic number, because the mean of its divisors is an integer number (66704959269).

Almost surely, 2^266666666657 is an apocalyptic number.

It is an amenable number.

266666666657 is a deficient number, since it is larger than the sum of its proper divisors (153170419).

266666666657 is a wasteful number, since it uses less digits than its factorization.

266666666657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153170418.

The product of its digits is 705438720, while the sum is 68.

The spelling of 266666666657 in words is "two hundred sixty-six billion, six hundred sixty-six million, six hundred sixty-six thousand, six hundred fifty-seven".