It is a happy number.
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79361 = 61 ⋅1301.
It is a cyclic number.
It is an Ulam number.
It is a Duffinian number.
It is a plaindrome in base 11.
It is a nialpdrome in base 7.
It is a congruent number.
216397 is an apocalyptic number.
It is an amenable number.
16397 is an equidigital number, since it uses as much as digits as its factorization.
16397 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 882.
The square root of 16397 is about 128.0507711808. The cubic root of 16397 is about 25.4051325731.
The spelling of 16397 in words is "sixteen thousand, three hundred ninety-seven".