129381 has 16 divisors (see below), whose sum is σ = 202368. Its totient is φ = 72000.

The previous prime is 129379. The next prime is 129401. The reversal of 129381 is 183921.

It is not a de Polignac number, because 129381 - 2¹ = 129379 is a prime.

It is a super-2 number, since 2×129381² = 33478886322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129341) 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 15 ways as a sum of consecutive naturals, for example, 1231 + ... + 1331.

It is an arithmetic number, because the mean of its divisors is an integer number (12648).

2¹²⁹³⁸¹ is an apocalyptic number.

It is an amenable number.

129381 is a deficient number, since it is larger than the sum of its proper divisors (72987).

129381 is a wasteful number, since it uses less digits than its factorization.

129381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172.

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

The square root of 129381 is about 359.6957047283. The cubic root of 129381 is about 50.5774389468.

The spelling of 129381 in words is "one hundred twenty-nine thousand, three hundred eighty-one".