129709 has 4 divisors (see below), whose sum is σ = 130720. Its totient is φ = 128700.

The previous prime is 129707. The next prime is 129719. The reversal of 129709 is 907921.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 129709 - 2¹ = 129707 is a prime.

It is a Duffinian number.

129709 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129707) 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, 279 + ... + 580.

It is an arithmetic number, because the mean of its divisors is an integer number (32680).

2¹²⁹⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

129709 is a deficient number, since it is larger than the sum of its proper divisors (1011).

129709 is an equidigital number, since it uses as much as digits as its factorization.

129709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010.

The product of its (nonzero) digits is 1134, while the sum is 28.

The square root of 129709 is about 360.1513570709. The cubic root of 129709 is about 50.6201433130.

It can be divided in two parts, 129 and 709, that added together give a palindrome (838).

The spelling of 129709 in words is "one hundred twenty-nine thousand, seven hundred nine".