129147999 has 4 divisors (see below), whose sum is σ = 172197336. Its totient is φ = 86098664.

The previous prime is 129147979. The next prime is 129148007. The reversal of 129147999 is 999741921.

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 129147999 - 2²⁰ = 128099423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129147979) 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, 21524664 + ... + 21524669.

It is an arithmetic number, because the mean of its divisors is an integer number (43049334).

Almost surely, 2^129147999 is an apocalyptic number.

129147999 is a deficient number, since it is larger than the sum of its proper divisors (43049337).

129147999 is an equidigital number, since it uses as much as digits as its factorization.

129147999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43049336.

The product of its digits is 367416, while the sum is 51.

The square root of 129147999 is about 11364.3301166413. The cubic root of 129147999 is about 505.4705922796.

The spelling of 129147999 in words is "one hundred twenty-nine million, one hundred forty-seven thousand, nine hundred ninety-nine".