129666 has 8 divisors (see below), whose sum is σ = 259344. Its totient is φ = 43220.

The previous prime is 129643. The next prime is 129671. The reversal of 129666 is 666921.

129666 is nontrivially palindromic in base 5.

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

129666 is an admirable number.

It is an unprimeable number.

129666 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10800 + ... + 10811.

It is an arithmetic number, because the mean of its divisors is an integer number (32418).

2¹²⁹⁶⁶⁶ is an apocalyptic number.

129666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129666 is a wasteful number, since it uses less digits than its factorization.

129666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21616.

The product of its digits is 3888, while the sum is 30.

The square root of 129666 is about 360.0916549991. The cubic root of 129666 is about 50.6145489781.

The spelling of 129666 in words is "one hundred twenty-nine thousand, six hundred sixty-six".