BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

130-point score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

number of digits in a factorial

Expert replies
by krazy800 » Tue Jun 09, 2009 1:02 am
Folks,
How can we determine number of digits for factorial of a number? For example, how many digits are there in 16!? Is there any generalized procedure?

Appreciate your inputs.
Aiming High
Join the discussion
Source: — Problem Solving |

by yogami » Tue Jun 09, 2009 1:11 am
I will be surprised if there is one. And if there is one then you have to memorize it as I won't be able to derive that within 2 minutes in real GMAT unless lightning strikes my brain and I turn into a genius.
200 or 800. It don't matter no more.
Join the discussion

by yogami » Tue Jun 09, 2009 1:18 am
1! to 3! num of digits 1
4! num of digits 2
5! and 6! num of digits 3
and after this through 13! the num of digits is always three less than the factorial i.e. for 13! it is 10 digits...


for 14 and beyond i have no idea and patience to find out ;)
200 or 800. It don't matter no more.
Join the discussion