It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 156461 = 97 ⋅1613.
It is a cyclic number.
It is a Duffinian number.
It is a plaindrome in base 15.
It is a zygodrome in base 15.
2164651 is an apocalyptic number.
164651 is an equidigital number, since it uses as much as digits as its factorization.
164651 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 948.
The square root of 164651 is about 405.7721035261. The cubic root of 164651 is about 54.8093675712.
The spelling of 164651 in words is "one hundred sixty-four thousand, six hundred fifty-one".