129171911 has 4 divisors (see below), whose sum is σ = 140914824. Its totient is φ = 117429000.

The previous prime is 129171869. The next prime is 129171923. The reversal of 129171911 is 119171921.

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 129171911 - 2¹⁰ = 129170887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129171941) 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, 5871440 + ... + 5871461.

It is an arithmetic number, because the mean of its divisors is an integer number (35228706).

Almost surely, 2^129171911 is an apocalyptic number.

129171911 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

129171911 is a deficient number, since it is larger than the sum of its proper divisors (11742913).

129171911 is a wasteful number, since it uses less digits than its factorization.

129171911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11742912.

The product of its digits is 1134, while the sum is 32.

The square root of 129171911 is about 11365.3821317191. The cubic root of 129171911 is about 505.5017866380.

The spelling of 129171911 in words is "one hundred twenty-nine million, one hundred seventy-one thousand, nine hundred eleven".