I kept dividing by 2 until I got an odd number: 8124287104÷2 = 4062143662 4062143552÷2 = 2031071776 2031071776÷2 = 1015535888 1015535888÷2 = 507767944 507767944÷2 = 253883972 253883972÷2 = 126941986 126941986÷2 = 63470993 <--an odd number So 8124287104 = 27∙63470993 We know that 26 = (23)2 = 82 = 64 is a perfect square that divides 8124287104. But we don't know if there is a larger one. So I went to http://compoasso.free.fr/primelistweb/page/prime/liste_online_en.php and typed in 63470993 to see if it is prime and found that it was not. So I tried dividing it by primes 3,5,7,11,13,17,19,23,29,31,37,41 and found that 63470993 = 41∙1548073 I went to that site again and found that 1548073 is indeed a prime. So 64 is the largest perfect square that divides 8124287104. 64 has two square roots, which are 8 and -8. Edwin