129709247 has 4 divisors (see below), whose sum is σ = 131486160. Its totient is φ = 127932336.

The previous prime is 129709207. The next prime is 129709267. The reversal of 129709247 is 742907921.

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 129709247 - 2⁶ = 129709183 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 (129709207) 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, 888347 + ... + 888492.

It is an arithmetic number, because the mean of its divisors is an integer number (32871540).

Almost surely, 2^129709247 is an apocalyptic number.

129709247 is a deficient number, since it is larger than the sum of its proper divisors (1776913).

129709247 is an equidigital number, since it uses as much as digits as its factorization.

129709247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1776912.

The product of its (nonzero) digits is 63504, while the sum is 41.

The square root of 129709247 is about 11388.9967512507. The cubic root of 129709247 is about 506.2017544431.

The spelling of 129709247 in words is "one hundred twenty-nine million, seven hundred nine thousand, two hundred forty-seven".