12
No prime power exists since there are no duplicate prime numbers in the prime factorization.
34 = 81
19 x 73 = 1387. You can put the exponent 1 after all the numbers, but it's not necessary.
Yes.
No 5291 is not a prime using 2 numbers. It is a prime using three numbers.
3^2
24*35 = 3888
3,888 = 24 x 35
40 = 23 x 51
22 x 89 = 356
Prime factors in exponent form: 2^4 * 11
23 x 3 x 72