39809 has 12 divisors (see below), whose sum is σ = 51072. Its totient is φ = 30360.

The previous prime is 39799. The next prime is 39821. The reversal of 39809 is 90893.

It is a de Polignac number, because none of the positive numbers 2^k-39809 is a prime.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (39829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 824 + ... + 870.

It is an arithmetic number, because the mean of its divisors is an integer number (4256).

2³⁹⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

39809 is a deficient number, since it is larger than the sum of its proper divisors (11263).

39809 is a wasteful number, since it uses less digits than its factorization.

39809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 39809 is about 199.5219286194. The cubic root of 39809 is about 34.1449978275.

It can be divided in two parts, 39 and 809, that added together give a palindrome (848).

The spelling of 39809 in words is "thirty-nine thousand, eight hundred nine".