266820 has 24 divisors (see below), whose sum is σ = 747264. Its totient is φ = 71136.

The previous prime is 266801. The next prime is 266821. The reversal of 266820 is 28662.

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 266820.

It is not an unprimeable number, because it can be changed into a prime (266821) by changing a digit.

266820 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2164 + ... + 2283.

It is an arithmetic number, because the mean of its divisors is an integer number (31136).

2²⁶⁶⁸²⁰ is an apocalyptic number.

266820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

266820 is an abundant number, since it is smaller than the sum of its proper divisors (480444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

266820 is a wasteful number, since it uses less digits than its factorization.

266820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4459 (or 4457 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 266820 is about 516.5462225203. The cubic root of 266820 is about 64.3782934187.

The spelling of 266820 in words is "two hundred sixty-six thousand, eight hundred twenty".