129179231 has 4 divisors (see below), whose sum is σ = 130165464. Its totient is φ = 128193000.

The previous prime is 129179213. The next prime is 129179249. The reversal of 129179231 is 132971921.

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

It is an interprime number because it is at equal distance from previous prime (129179213) and next prime (129179249).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129179231 is a prime.

It is a super-2 number, since 2×129179231² = 33374547443502722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 129179191 and 129179200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129179131) 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, 492920 + ... + 493181.

It is an arithmetic number, because the mean of its divisors is an integer number (32541366).

Almost surely, 2^129179231 is an apocalyptic number.

129179231 is a deficient number, since it is larger than the sum of its proper divisors (986233).

129179231 is an equidigital number, since it uses as much as digits as its factorization.

129179231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986232.

The product of its digits is 6804, while the sum is 35.

The square root of 129179231 is about 11365.7041576842. The cubic root of 129179231 is about 505.5113351618.

The spelling of 129179231 in words is "one hundred twenty-nine million, one hundred seventy-nine thousand, two hundred thirty-one".