16405 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.
It is a sphenic number, since it is the product of 3 distinct primes.
It is a 6-Lehmer number, since φ(16405) divides (16405-1)6.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-16405 is a prime.
It is a Duffinian number.
16405 is strictly pandigital in base 6.
It is a plaindrome in base 9.
It is a nialpdrome in base 7.
It is a congruent number.
It is an unprimeable number.
216405 is an apocalyptic number.
It is an amenable number.
16405 is a wasteful number, since it uses less digits than its factorization.
16405 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 215.
The square root of 16405 is about 128.0820049812. The cubic root of 16405 is about 25.4092635730.
Adding to 16405 its reverse (50461), we get a palindrome (66866).
The spelling of 16405 in words is "sixteen thousand, four hundred five".