3981

3981 = 3 x 1327.

3981 is the largest number whose fifth power has 18 digits (A114323).

3981 is 111411 in base 5.

3981 is a power of the fifth root of 100, rounded to the nearest integer (A205770).

The aliquot divisors of 3981 sum to a cube (A048698).

Source: OEIS