129444639 has 4 divisors (see below), whose sum is σ = 172592856. Its totient is φ = 86296424.

The previous prime is 129444631. The next prime is 129444649. The reversal of 129444639 is 936444921.

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 129444639 - 2³ = 129444631 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 129444639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129444631) 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, 21574104 + ... + 21574109.

It is an arithmetic number, because the mean of its divisors is an integer number (43148214).

Almost surely, 2^129444639 is an apocalyptic number.

129444639 is a deficient number, since it is larger than the sum of its proper divisors (43148217).

129444639 is an equidigital number, since it uses as much as digits as its factorization.

129444639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43148216.

The product of its digits is 186624, while the sum is 42.

The square root of 129444639 is about 11377.3739940287. The cubic root of 129444639 is about 505.8573014368.

The spelling of 129444639 in words is "one hundred twenty-nine million, four hundred forty-four thousand, six hundred thirty-nine".