129516979 has 4 divisors (see below), whose sum is σ = 135148176. Its totient is φ = 123885784.

The previous prime is 129516971. The next prime is 129517009. The reversal of 129516979 is 979615921.

129516979 = 2362² + 2363² + ... + 2384².

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 129516979 - 2³ = 129516971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129516971) 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, 2815564 + ... + 2815609.

It is an arithmetic number, because the mean of its divisors is an integer number (33787044).

Almost surely, 2^129516979 is an apocalyptic number.

129516979 is a deficient number, since it is larger than the sum of its proper divisors (5631197).

129516979 is an equidigital number, since it uses as much as digits as its factorization.

129516979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5631196.

The product of its digits is 306180, while the sum is 49.

The square root of 129516979 is about 11380.5526667205. The cubic root of 129516979 is about 505.9515164949.

The spelling of 129516979 in words is "one hundred twenty-nine million, five hundred sixteen thousand, nine hundred seventy-nine".