66909 has 4 divisors (see below), whose sum is σ = 89216. Its totient is φ = 44604.

The previous prime is 66889. The next prime is 66919. The reversal of 66909 is 90966.

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.

It is not a de Polignac number, because 66909 - 2⁵ = 66877 is a prime.

It is a D-number.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66919) 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, 11149 + ... + 11154.

It is an arithmetic number, because the mean of its divisors is an integer number (22304).

2⁶⁶⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

66909 is a deficient number, since it is larger than the sum of its proper divisors (22307).

66909 is a wasteful number, since it uses less digits than its factorization.

66909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22306.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 66909 is about 258.6677405476. The cubic root of 66909 is about 40.5970845699.

The spelling of 66909 in words is "sixty-six thousand, nine hundred nine".