129939 has 4 divisors (see below), whose sum is σ = 173256. Its totient is φ = 86624.

The previous prime is 129937. The next prime is 129953. The reversal of 129939 is 939921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 939921 = 3 ⋅313307.

It is a cyclic number.

It is not a de Polignac number, because 129939 - 2¹ = 129937 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (129937) 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, 21654 + ... + 21659.

It is an arithmetic number, because the mean of its divisors is an integer number (43314).

2¹²⁹⁹³⁹ is an apocalyptic number.

129939 is a deficient number, since it is larger than the sum of its proper divisors (43317).

129939 is an equidigital number, since it uses as much as digits as its factorization.

129939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43316.

The product of its digits is 4374, while the sum is 33.

The square root of 129939 is about 360.4705258409. The cubic root of 129939 is about 50.6500455253.

The spelling of 129939 in words is "one hundred twenty-nine thousand, nine hundred thirty-nine".