139809 has 8 divisors (see below), whose sum is σ = 192960. Its totient is φ = 89936.

The previous prime is 139801. The next prime is 139813. The reversal of 139809 is 908931.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 139809 - 2³ = 139801 is a prime.

It is a Curzon number.

139809 is a lucky number.

It is a nialpdrome in base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 139809.

It is not an unprimeable number, because it can be changed into a prime (139801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 717 + ... + 890.

It is an arithmetic number, because the mean of its divisors is an integer number (24120).

2¹³⁹⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

139809 is a deficient number, since it is larger than the sum of its proper divisors (53151).

139809 is a wasteful number, since it uses less digits than its factorization.

139809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1639.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 139809 is about 373.9104170787. The cubic root of 139809 is about 51.9013167868.

The spelling of 139809 in words is "one hundred thirty-nine thousand, eight hundred nine".