Q: Is 261,640 a Prime Number?
A: No, 261,640 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 261640 can be evenly divided by 1 2 4 5 8 10 20 31 40 62 124 155 211 248 310 422 620 844 1,055 1,240 1,688 2,110 4,220 6,541 8,440 13,082 26,164 32,705 52,328 65,410 130,820 and 261,640, with no remainder.
Since 261,640 cannot be divided by just 1 and 261,640, it is not a prime number.