What is the smallest number with exactly 14 divisors?
Many numbers can be expressed as the sum of two or more consecutive integers. For example, 15=7+8 and 10=1+2+3+4. Can you say which numbers can be expressed in this way?
Helen made the conjecture that "every multiple of six has more factors than the two numbers either side of it". Is this conjecture true?
This challenge is to make up YOUR OWN alphanumeric. Each letter represents a digit and where the same letter appears more than once it must represent the same digit each time. The hard part is to make up some message rather than just using any old letters. Send in your alphanumeric together with at least one solution to it. Another challenge is to discover if the puzzle has just one solution or many. Here are two easy examples; they are just addition sums and you may be more inventive and make up subtractions, multiplications or divisions:
Lastly, can you prove that
cannot be made into an alphnumeric?