66805 has 8 divisors (see below), whose sum is σ = 82944. Its totient is φ = 51600.

The previous prime is 66797. The next prime is 66809. The reversal of 66805 is 50866.

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

It is not a de Polignac number, because 66805 - 2³ = 66797 is a prime.

It is a Duffinian number.

It is a plaindrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 66805.

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 7 ways as a sum of consecutive naturals, for example, 61 + ... + 370.

It is an arithmetic number, because the mean of its divisors is an integer number (10368).

2⁶⁶⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

66805 is a deficient number, since it is larger than the sum of its proper divisors (16139).

66805 is a wasteful number, since it uses less digits than its factorization.

66805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 66805 is about 258.4666322758. The cubic root of 66805 is about 40.5760396371.

The spelling of 66805 in words is "sixty-six thousand, eight hundred five".