129831 has 8 divisors (see below), whose sum is σ = 186480. Its totient is φ = 79872.

The previous prime is 129803. The next prime is 129841. The reversal of 129831 is 138921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-129831 is a prime.

It is a super-2 number, since 2×129831² = 33712177122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

129831 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1626 + ... + 1703.

It is an arithmetic number, because the mean of its divisors is an integer number (23310).

2¹²⁹⁸³¹ is an apocalyptic number.

129831 is a deficient number, since it is larger than the sum of its proper divisors (56649).

129831 is a wasteful number, since it uses less digits than its factorization.

129831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3345.

The product of its digits is 432, while the sum is 24.

The square root of 129831 is about 360.3206904967. The cubic root of 129831 is about 50.6360088846.

The spelling of 129831 in words is "one hundred twenty-nine thousand, eight hundred thirty-one".