Write the prime decomposition of the following numbers:
(a) 53 (b) 530 (c) 1988 (d) 666 (e) 2021
(a) 53 has no prime decomposition as it is prime itself.
(b) $53 = 2 \times 5 \times 53$
(c) $ 1988 = 2^2 \times 7 \times 71 $
(d) $ 2 \times 3^2 \times 37 $
(e) $ 2021 = 43 \times 47 $