129817 has 4 divisors (see below), whose sum is σ = 132880. Its totient is φ = 126756.

The previous prime is 129803. The next prime is 129841. The reversal of 129817 is 718921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129887) 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 3 ways as a sum of consecutive naturals, for example, 1467 + ... + 1552.

It is an arithmetic number, because the mean of its divisors is an integer number (33220).

2¹²⁹⁸¹⁷ is an apocalyptic number.

It is an amenable number.

129817 is a deficient number, since it is larger than the sum of its proper divisors (3063).

129817 is an equidigital number, since it uses as much as digits as its factorization.

129817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3062.

The product of its digits is 1008, while the sum is 28.

The square root of 129817 is about 360.3012628343. The cubic root of 129817 is about 50.6341887502.

It can be divided in two parts, 129 and 817, that added together give a triangular number (946 = T₄₃).

The spelling of 129817 in words is "one hundred twenty-nine thousand, eight hundred seventeen".