> Probably doesn't fit precisely into a double. Does strtold behave > better?
actually both numbers can be represented exactly as IEEE double. In Maxima: (%i1) factor(121645100408832000); (%o1) 2^16*3^8*5^3*7^2*11*13*17*19 (%i2) float(log(3^8*5^3*7^2*11*13*17*19)/log(2)); (%o2) 40.75545582601886 (%i3) factor(221645100408832000); (%o3) 2^16*5^3*31*41*1361*15641 (%i4) float(log(5^3*31*41*1361*15641)/log(2)); (%o4) 41.62102908434535 So the first number has 41 bits and the second 42 after removing powers of 2. The significand size of a double is 53 bits (including the implicit 1). Best regards, Michael Intel Deutschland GmbH Registered Address: Am Campeon 10-12, 85579 Neubiberg, Germany Tel: +49 89 99 8853-0, www.intel.de Managing Directors: Christin Eisenschmid, Christian Lamprechter Chairperson of the Supervisory Board: Nicole Lau Registered Office: Munich Commercial Register: Amtsgericht Muenchen HRB 186928