139830809 has 4 divisors (see below), whose sum is σ = 141917904. Its totient is φ = 137743716.

The previous prime is 139830799. The next prime is 139830811. The reversal of 139830809 is 908038931.

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, and also an emirpimes, since its reverse is a distinct semiprime: 908038931 = 41 ⋅22147291.

It is a cyclic number.

It is not a de Polignac number, because 139830809 - 2⁴ = 139830793 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (139833809) 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, 1043447 + ... + 1043580.

It is an arithmetic number, because the mean of its divisors is an integer number (35479476).

Almost surely, 2^139830809 is an apocalyptic number.

It is an amenable number.

139830809 is a deficient number, since it is larger than the sum of its proper divisors (2087095).

139830809 is an equidigital number, since it uses as much as digits as its factorization.

139830809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2087094.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 139830809 is about 11825.0077801243. The cubic root of 139830809 is about 519.0401536594.

The spelling of 139830809 in words is "one hundred thirty-nine million, eight hundred thirty thousand, eight hundred nine".