129665 has 4 divisors (see below), whose sum is σ = 155604. Its totient is φ = 103728.

The previous prime is 129643. The next prime is 129671. The reversal of 129665 is 566921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37249 + 92416 = 193^2 + 304^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129665 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12962 + ... + 12971.

It is an arithmetic number, because the mean of its divisors is an integer number (38901).

2¹²⁹⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

129665 is a deficient number, since it is larger than the sum of its proper divisors (25939).

129665 is an equidigital number, since it uses as much as digits as its factorization.

129665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25938.

The product of its digits is 3240, while the sum is 29.

The square root of 129665 is about 360.0902664611. The cubic root of 129665 is about 50.6144188626.

The spelling of 129665 in words is "one hundred twenty-nine thousand, six hundred sixty-five".