129323881 has 4 divisors (see below), whose sum is σ = 132478164. Its totient is φ = 126169600.

The previous prime is 129323839. The next prime is 129323891. The reversal of 129323881 is 188323921.

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 10949481 + 118374400 = 3309^2 + 10880^2 .

It is a cyclic number.

It is not a de Polignac number, because 129323881 - 2²³ = 120935273 is a prime.

It is a super-2 number, since 2×129323881² = 33449332393804322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 129323881.

It is not an unprimeable number, because it can be changed into a prime (129323801) 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, 1577080 + ... + 1577161.

It is an arithmetic number, because the mean of its divisors is an integer number (33119541).

Almost surely, 2^129323881 is an apocalyptic number.

It is an amenable number.

129323881 is a deficient number, since it is larger than the sum of its proper divisors (3154283).

129323881 is an equidigital number, since it uses as much as digits as its factorization.

129323881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3154282.

The product of its digits is 20736, while the sum is 37.

The square root of 129323881 is about 11372.0658193663. The cubic root of 129323881 is about 505.6999489141.

The spelling of 129323881 in words is "one hundred twenty-nine million, three hundred twenty-three thousand, eight hundred eighty-one".