A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 739704 can be evenly divided by 1 2 3 4 6 7 8 12 14 17 21 24 28 34 37 42 49 51 56 68 74 84 98 102 111 119 136 147 148 168 196 204 222 238 259 294 296 357 392 408 444 476 518 588 629 714 777 833 888 952 1,036 1,176 1,258 1,428 1,554 1,666 1,813 1,887 2,072 2,499 2,516 2,856 3,108 3,332 3,626 3,774 4,403 4,998 5,032 5,439 6,216 6,664 7,252 7,548 8,806 9,996 10,878 13,209 14,504 15,096 17,612 19,992 21,756 26,418 30,821 35,224 43,512 52,836 61,642 92,463 105,672 123,284 184,926 246,568 369,852 and 739,704, with no remainder.
Since 739,704 cannot be divided by just 1 and 739,704, it is not a prime number.