challenge - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: Not HP Calculators (/forum-7.html) +--- Forum: Not remotely HP Calculators (/forum-9.html) +--- Thread: challenge (/thread-9505.html) challenge - Don Shepherd - 11-16-2017 01:03 AM Without using a CAS or the Internet, how many factors does this number have: 200,560,490,130? RE: challenge - Paul Dale - 11-16-2017 01:20 AM Prime factorisation by hand didn't take long and it revealed 11 factors. Each can be present or absent for each factor so 211 = 2048 in total. Pauli RE: challenge - Don Shepherd - 11-16-2017 01:30 AM (11-16-2017 01:20 AM)Paul Dale Wrote:  Prime factorisation by hand didn't take long and it revealed 11 factors. Each can be present or absent for each factor so 211 = 2048 in total. Pauli Congratulations Pauli! 200,560,490,130 is the product of the first 11 prime numbers. To find the total number of factors of a number, determine the numbers prime factors, then add 1 to each exponent and then multiply those numbers together: 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 2,048