66800 has 30 divisors (see below), whose sum is σ = 161448. Its totient is φ = 26560.

The previous prime is 66797. The next prime is 66809. The reversal of 66800 is 866.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66809) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 317 + ... + 483.

2⁶⁶⁸⁰⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80724).

66800 is an abundant number, since it is smaller than the sum of its proper divisors (94648).

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

66800 is a wasteful number, since it uses less digits than its factorization.

66800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 174 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 66800 is about 258.4569596664. The cubic root of 66800 is about 40.5750273113.

The spelling of 66800 in words is "sixty-six thousand, eight hundred".