129168231 has 4 divisors (see below), whose sum is σ = 172224312. Its totient is φ = 86112152.

The previous prime is 129168229. The next prime is 129168301. The reversal of 129168231 is 132861921.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 129168231 - 2¹ = 129168229 is a prime.

It is a super-2 number, since 2×129168231² = 33368863799338722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 129168192 and 129168201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129168211) 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, 21528036 + ... + 21528041.

It is an arithmetic number, because the mean of its divisors is an integer number (43056078).

Almost surely, 2^129168231 is an apocalyptic number.

129168231 is a deficient number, since it is larger than the sum of its proper divisors (43056081).

129168231 is an equidigital number, since it uses as much as digits as its factorization.

129168231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43056080.

The product of its digits is 5184, while the sum is 33.

The square root of 129168231 is about 11365.2202354376. The cubic root of 129168231 is about 505.4969861510.

The spelling of 129168231 in words is "one hundred twenty-nine million, one hundred sixty-eight thousand, two hundred thirty-one".