Q: Is 19,840 a Prime Number?
A: No, 19,840 is not a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 19840 can be evenly divided by 1 2 4 5 8 10 16 20 31 32 40 62 64 80 124 128 155 160 248 310 320 496 620 640 992 1,240 1,984 2,480 3,968 4,960 9,920 and 19,840, with no remainder.
Since 19,840 cannot be divided by just 1 and 19,840, it is not a prime number.