It is a semiprime because it is the product of two primes.
It is an Ulam number.
It is a plaindrome in base 12.
It is a nialpdrome in base 8.
It is an unprimeable number.
3994 is a wasteful number, since it uses less digits than its factorization.
3994 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1999.
The square root of 3994 is about 63.1981012373. The cubic root of 3994 is about 15.8660695426.
Subtracting from 3994 its sum of digits (25), we obtain a square (3969 = 632).
Subtracting 3994 from its reverse (4993), we obtain a palindrome (999).
The spelling of 3994 in words is "three thousand, nine hundred ninety-four".