129785439 has 8 divisors (see below), whose sum is σ = 197768320. Its totient is φ = 74163096.

The previous prime is 129785413. The next prime is 129785441. The reversal of 129785439 is 934587921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-129785439 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 (129785449) 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 7 ways as a sum of consecutive naturals, for example, 3090109 + ... + 3090150.

It is an arithmetic number, because the mean of its divisors is an integer number (24721040).

Almost surely, 2^129785439 is an apocalyptic number.

129785439 is a deficient number, since it is larger than the sum of its proper divisors (67982881).

129785439 is an equidigital number, since it uses as much as digits as its factorization.

129785439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6180269.

The product of its digits is 544320, while the sum is 48.

The square root of 129785439 is about 11392.3412431335. The cubic root of 129785439 is about 506.3008503715.

It can be divided in two parts, 1297 and 85439, that added together give a triangular number (86736 = T₄₁₆).

The spelling of 129785439 in words is "one hundred twenty-nine million, seven hundred eighty-five thousand, four hundred thirty-nine".