Q: Is 121,905 a Prime Number?
A: No, 121,905 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 121905 can be evenly divided by 1 3 5 7 9 15 21 27 35 43 45 63 81 105 129 135 189 215 301 315 387 405 567 645 903 945 1,161 1,505 1,935 2,709 2,835 3,483 4,515 5,805 8,127 13,545 17,415 24,381 40,635 and 121,905, with no remainder.
Since 121,905 cannot be divided by just 1 and 121,905, it is not a prime number.