Helen's Conjecture

Problem | Solution | Printable page |
Stage: 3 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Helen made the conjecture that "every multiple of six has more factors than the two numbers either side of it". Is this conjecture true?

For example, the third multiple of 6 is 18 which has six factors (counting 1 and 18), while 17 and 19, the numbers on each side of it, have two each being prime.

Published December 1997.