129889 has 4 divisors (see below), whose sum is σ = 130756. Its totient is φ = 129024.

The previous prime is 129887. The next prime is 129893. The reversal of 129889 is 988921.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 988921 = 163 ⋅6067.

It can be written as a sum of positive squares in 2 ways, for example, as 36864 + 93025 = 192^2 + 305^2 .

It is a cyclic number.

It is not a de Polignac number, because 129889 - 2¹ = 129887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144 + ... + 529.

It is an arithmetic number, because the mean of its divisors is an integer number (32689).

It is a Poulet number, since it divides 2¹²⁹⁸⁸⁸-1.

2¹²⁹⁸⁸⁹ is an apocalyptic number.

129889 is the 193-rd nonagonal number.

It is an amenable number.

129889 is a deficient number, since it is larger than the sum of its proper divisors (867).

129889 is an equidigital number, since it uses as much as digits as its factorization.

129889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 866.

The product of its digits is 10368, while the sum is 37.

The square root of 129889 is about 360.4011653699. The cubic root of 129889 is about 50.6435480478.

It can be divided in two parts, 1 and 29889, that added together give a triangular number (29890 = T₂₄₄).

The spelling of 129889 in words is "one hundred twenty-nine thousand, eight hundred eighty-nine".