123129 has 6 divisors (see below), whose sum is σ = 177866. Its totient is φ = 82080.

The previous prime is 123127. The next prime is 123143. The reversal of 123129 is 921321.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 121104 + 2025 = 348^2 + 45^2 .

It is not a de Polignac number, because 123129 - 2¹ = 123127 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6832 + ... + 6849.

2¹²³¹²⁹ is an apocalyptic number.

It is an amenable number.

123129 is a deficient number, since it is larger than the sum of its proper divisors (54737).

123129 is a wasteful number, since it uses less digits than its factorization.

123129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13687 (or 13684 counting only the distinct ones).

The product of its digits is 108, while the sum is 18.

The square root of 123129 is about 350.8974209082. The cubic root of 123129 is about 49.7492782064.

It can be divided in two parts, 12312 and 9, that added together give a palindrome (12321).

The spelling of 123129 in words is "one hundred twenty-three thousand, one hundred twenty-nine".