129565 has 4 divisors (see below), whose sum is σ = 155484. Its totient is φ = 103648.

The previous prime is 129553. The next prime is 129581. The reversal of 129565 is 565921.

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 63001 + 66564 = 251^2 + 258^2 .

It is a cyclic number.

It is not a de Polignac number, because 129565 - 2⁵ = 129533 is a prime.

It is a super-4 number, since 4×129565⁴ (a number of 22 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 12952 + ... + 12961.

It is an arithmetic number, because the mean of its divisors is an integer number (38871).

2¹²⁹⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

129565 is a deficient number, since it is larger than the sum of its proper divisors (25919).

129565 is an equidigital number, since it uses as much as digits as its factorization.

129565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25918.

The product of its digits is 2700, while the sum is 28.

The square root of 129565 is about 359.9513856064. The cubic root of 129565 is about 50.6014039303.

The spelling of 129565 in words is "one hundred twenty-nine thousand, five hundred sixty-five".