129605 has 18 divisors (see below), whose sum is σ = 189126. Its totient is φ = 85008.

The previous prime is 129593. The next prime is 129607. The reversal of 129605 is 506921.

It can be written as a sum of positive squares in only one way, i.e., 103684 + 25921 = 322^2 + 161^2 .

It is not a de Polignac number, because 129605 - 2⁴ = 129589 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129607) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 5624 + ... + 5646.

It is an arithmetic number, because the mean of its divisors is an integer number (10507).

129605 is a Friedman number, since it can be written as 90^2*16+5, using all its digits and the basic arithmetic operations.

2¹²⁹⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

129605 is a deficient number, since it is larger than the sum of its proper divisors (59521).

129605 is an equidigital number, since it uses as much as digits as its factorization.

129605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65 (or 35 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 129605 is about 360.0069443775. The cubic root of 129605 is about 50.6066107065.

The spelling of 129605 in words is "one hundred twenty-nine thousand, six hundred five".