EXPT function returns base-number raised to the power-number.

(expt 2 8) => 256
(expt 2 32) => 4294967296
(expt 2 64) => 18446744073709551616
(expt 10 3) => 1000
(expt 5 1/3) => 1.709976
(expt 1.709976 3) => 5.0

(expt 1 2) => 1
(expt 1.0 2) => 1.0
(expt 1.0d0 2) => 1.0d0
(expt -2 5) => -32
(expt 2 2.5) => 5.656854
(expt -2 2.5) => #C(1.7318549e-15 5.656854)
(expt 2 -3) => 1/8
(expt -2 -3) => -1/8
(expt -2.4 -3) => -0.072337955
(expt -2.4 -3.3) => #C(-0.032698035 0.045004968)

(expt (expt 10 5) 1/5) => 10.0