129872717 has 4 divisors (see below), whose sum is σ = 139862940. Its totient is φ = 119882496.

The previous prime is 129872713. The next prime is 129872783. The reversal of 129872717 is 717278921.

It is a happy number.

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 58537801 + 71334916 = 7651^2 + 8446^2 .

It is a cyclic number.

It is not a de Polignac number, because 129872717 - 2² = 129872713 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 (129872711) 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, 4995092 + ... + 4995117.

It is an arithmetic number, because the mean of its divisors is an integer number (34965735).

Almost surely, 2^129872717 is an apocalyptic number.

It is an amenable number.

129872717 is a deficient number, since it is larger than the sum of its proper divisors (9990223).

129872717 is an equidigital number, since it uses as much as digits as its factorization.

129872717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9990222.

The product of its digits is 98784, while the sum is 44.

The square root of 129872717 is about 11396.1711552609. The cubic root of 129872717 is about 506.4143171936.

The spelling of 129872717 in words is "one hundred twenty-nine million, eight hundred seventy-two thousand, seven hundred seventeen".