266861 has 8 divisors (see below), whose sum is σ = 310080. Its totient is φ = 224928.

The previous prime is 266839. The next prime is 266863. The reversal of 266861 is 168662.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 266861 - 2⁶ = 266797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 185 + ... + 753.

It is an arithmetic number, because the mean of its divisors is an integer number (38760).

2²⁶⁶⁸⁶¹ is an apocalyptic number.

It is an amenable number.

266861 is a deficient number, since it is larger than the sum of its proper divisors (43219).

266861 is an equidigital number, since it uses as much as digits as its factorization.

266861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643.

The product of its digits is 3456, while the sum is 29.

The square root of 266861 is about 516.5859076669. The cubic root of 266861 is about 64.3815907413.

The spelling of 266861 in words is "two hundred sixty-six thousand, eight hundred sixty-one".