129708749 has 4 divisors (see below), whose sum is σ = 129856860. Its totient is φ = 129560640.

The previous prime is 129708739. The next prime is 129708779. The reversal of 129708749 is 947807921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62173225 + 67535524 = 7885^2 + 8218^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129708749 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 (129708739) 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 3 ways as a sum of consecutive naturals, for example, 72734 + ... + 74495.

It is an arithmetic number, because the mean of its divisors is an integer number (32464215).

Almost surely, 2^129708749 is an apocalyptic number.

It is an amenable number.

129708749 is a deficient number, since it is larger than the sum of its proper divisors (148111).

129708749 is an equidigital number, since it uses as much as digits as its factorization.

129708749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148110.

The product of its (nonzero) digits is 254016, while the sum is 47.

The square root of 129708749 is about 11388.9748880222. The cubic root of 129708749 is about 506.2011066127.

The spelling of 129708749 in words is "one hundred twenty-nine million, seven hundred eight thousand, seven hundred forty-nine".