129745309 has 8 divisors (see below), whose sum is σ = 139260600. Its totient is φ = 120439296.

The previous prime is 129745303. The next prime is 129745313. The reversal of 129745309 is 903547921.

129745309 = 1297² + 1298² + ... + 1369².

It can be written as a sum of positive squares in 4 ways, for example, as 30802500 + 98942809 = 5550^2 + 9947^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 129745309 - 2¹³ = 129737117 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129745303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51034 + ... + 53515.

It is an arithmetic number, because the mean of its divisors is an integer number (17407575).

Almost surely, 2^129745309 is an apocalyptic number.

It is an amenable number.

129745309 is a deficient number, since it is larger than the sum of its proper divisors (9515291).

129745309 is a wasteful number, since it uses less digits than its factorization.

129745309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104639.

The product of its (nonzero) digits is 68040, while the sum is 40.

The square root of 129745309 is about 11390.5798359873. The cubic root of 129745309 is about 506.2486618061.

The spelling of 129745309 in words is "one hundred twenty-nine million, seven hundred forty-five thousand, three hundred nine".