129808565 has 8 divisors (see below), whose sum is σ = 156113880. Its totient is φ = 103617792.

The previous prime is 129808561. The next prime is 129808577. The reversal of 129808565 is 565808921.

It can be written as a sum of positive squares in 4 ways, for example, as 3066001 + 126742564 = 1751^2 + 11258^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 129808565 - 2² = 129808561 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129808561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26120 + ... + 30689.

It is an arithmetic number, because the mean of its divisors is an integer number (19514235).

Almost surely, 2^129808565 is an apocalyptic number.

It is an amenable number.

129808565 is a deficient number, since it is larger than the sum of its proper divisors (26305315).

129808565 is an equidigital number, since it uses as much as digits as its factorization.

129808565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57271.

The product of its (nonzero) digits is 172800, while the sum is 44.

The square root of 129808565 is about 11393.3561780539. The cubic root of 129808565 is about 506.3309205606.

The spelling of 129808565 in words is "one hundred twenty-nine million, eight hundred eight thousand, five hundred sixty-five".