👉 In mathematics, "stirling's approximation" is a well-known formula that provides an upper bound on the number of distinct prime factors of a positive integer. It states that for any positive integer n: 1. If n is divisible by 2, then its prime factorization will consist of only two primes: 2 and the square root of n. 2. If n is not divisible by 2, then its prime factorization will consist of at least three primes: 3,