39666 has 16 divisors (see below), whose sum is σ = 86688. Its totient is φ = 12000.

The previous prime is 39659. The next prime is 39667. The reversal of 39666 is 66693.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (39667) by changing a digit.

39666 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 235 + ... + 366.

It is an arithmetic number, because the mean of its divisors is an integer number (5418).

2³⁹⁶⁶⁶ is an apocalyptic number.

39666 is an abundant number, since it is smaller than the sum of its proper divisors (47022).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43344).

39666 is a wasteful number, since it uses less digits than its factorization.

39666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617.

The product of its digits is 5832, while the sum is 30.

The square root of 39666 is about 199.1632496220. The cubic root of 39666 is about 34.1040640948.

It can be divided in two parts, 3 and 9666, that added together give a palindrome (9669).

The spelling of 39666 in words is "thirty-nine thousand, six hundred sixty-six".