129944399 has 4 divisors (see below), whose sum is σ = 139940136. Its totient is φ = 119948664.

The previous prime is 129944383. The next prime is 129944429. The reversal of 129944399 is 993449921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 993449921 = 197 ⋅5042893.

It is a cyclic number.

It is not a de Polignac number, because 129944399 - 2⁴ = 129944383 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 (129944329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4997849 + ... + 4997874.

It is an arithmetic number, because the mean of its divisors is an integer number (34985034).

Almost surely, 2^129944399 is an apocalyptic number.

129944399 is a deficient number, since it is larger than the sum of its proper divisors (9995737).

129944399 is an equidigital number, since it uses as much as digits as its factorization.

129944399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9995736.

The product of its digits is 629856, while the sum is 50.

The square root of 129944399 is about 11399.3157250775. The cubic root of 129944399 is about 506.5074702318.

The spelling of 129944399 in words is "one hundred twenty-nine million, nine hundred forty-four thousand, three hundred ninety-nine".