129669 has 4 divisors (see below), whose sum is σ = 172896. Its totient is φ = 86444.

The previous prime is 129643. The next prime is 129671. The reversal of 129669 is 966921.

It is a happy number.

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-129669 is a prime.

It is a super-2 number, since 2×129669² = 33628099122, which contains 22 as substring.

It is a D-number.

It is a Curzon number.

129669 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21609 + ... + 21614.

It is an arithmetic number, because the mean of its divisors is an integer number (43224).

2¹²⁹⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

129669 is a deficient number, since it is larger than the sum of its proper divisors (43227).

129669 is an equidigital number, since it uses as much as digits as its factorization.

129669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43226.

The product of its digits is 5832, while the sum is 33.

The square root of 129669 is about 360.0958205811. The cubic root of 129669 is about 50.6149393207.

The spelling of 129669 in words is "one hundred twenty-nine thousand, six hundred sixty-nine".