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: 371281661 = 3581 ⋅103681.
It is a cyclic number.
It is a Duffinian number.
It is a congruent number.
Almost surely, 2166182173 is an apocalyptic number.
It is an amenable number.
166182173 is an equidigital number, since it uses as much as digits as its factorization.
166182173 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 2816706.
The square root of 166182173 is about 12891.1664716580. The cubic root of 166182173 is about 549.7874363164.
The spelling of 166182173 in words is "one hundred sixty-six million, one hundred eighty-two thousand, one hundred seventy-three".