266389 has 4 divisors (see below), whose sum is σ = 267424. Its totient is φ = 265356.

The previous prime is 266381. The next prime is 266401. The reversal of 266389 is 983662.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 266389 - 2³ = 266381 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 (266381) 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, 214 + ... + 760.

It is an arithmetic number, because the mean of its divisors is an integer number (66856).

2²⁶⁶³⁸⁹ is an apocalyptic number.

It is an amenable number.

266389 is a deficient number, since it is larger than the sum of its proper divisors (1035).

266389 is an equidigital number, since it uses as much as digits as its factorization.

266389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1034.

The product of its digits is 15552, while the sum is 34.

The square root of 266389 is about 516.1288598790. The cubic root of 266389 is about 64.3436108637.

The spelling of 266389 in words is "two hundred sixty-six thousand, three hundred eighty-nine".