129129 has 32 divisors (see below), whose sum is σ = 236544. Its totient is φ = 60480.

The previous prime is 129127. The next prime is 129169. The reversal of 129129 is 921921.

129129 = T₅₅ + T₅₆ + ... + T₉₇.

It is not a de Polignac number, because 129129 - 2¹ = 129127 is a prime.

129129 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 129099 and 129108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2982 + ... + 3024.

It is an arithmetic number, because the mean of its divisors is an integer number (7392).

2¹²⁹¹²⁹ is an apocalyptic number.

It is an amenable number.

129129 is a deficient number, since it is larger than the sum of its proper divisors (107415).

129129 is a wasteful number, since it uses less digits than its factorization.

129129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77.

The product of its digits is 324, while the sum is 24.

The square root of 129129 is about 359.3452378980. The cubic root of 129129 is about 50.5445804422.

It can be divided in two parts, 12912 and 9, that added together give a palindrome (12921).

The spelling of 129129 in words is "one hundred twenty-nine thousand, one hundred twenty-nine".