What two number when multiplied equals 19991 (nineteen thousand nine hundred ninety one)?
From the aboves multiple we can see that 19991 is a multiple of 2 numbers.
The numbers are 1, 19991
These numbers are called the factors of 19991.
19991= 19991
A prime number is a number that is divisible only by 1 and itself (without a remainder).
19991 is a prime number because it has only two factors 1 and itself.
Lets learn factorization of other numbers.