Adding to 399001 its reverse (100993), we get a palindrome (499994).
399001 is nontrivially palindromic in base 5.
It is a sphenic number, since it is the product of 3 distinct primes.
It is a 3-Lehmer number, since φ(399001) divides (399001-1)3.
It is a cyclic number.
It is a Carmichael number.
It is a deceptive number, since it divides R399000.
It is a Poulet number, since it divides 2399000-1.
2399001 is an apocalyptic number.
399001 is a gapful number since it is divisible by the number (31) formed by its first and last digit.
399001 is the 400-th centered pentagonal number.
It is an amenable number.
399001 is a wasteful number, since it uses less digits than its factorization.
399001 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 303.
The square root of 399001 is about 631.6652594531. The cubic root of 399001 is about 73.6192397126.
The spelling of 399001 in words is "three hundred ninety-nine thousand, one".