166503 has 4 divisors (see below), whose sum is σ = 222008. Its totient is φ = 111000.

The previous prime is 166487. The next prime is 166541. The reversal of 166503 is 305661.

166503 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 166503 - 2⁴ = 166487 is a prime.

It is a D-number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27748 + ... + 27753.

It is an arithmetic number, because the mean of its divisors is an integer number (55502).

2¹⁶⁶⁵⁰³ is an apocalyptic number.

166503 is a deficient number, since it is larger than the sum of its proper divisors (55505).

166503 is an equidigital number, since it uses as much as digits as its factorization.

166503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55504.

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 166503 is about 408.0477913186. The cubic root of 166503 is about 55.0141010676.

It can be divided in two parts, 16650 and 3, that added together give a triangular number (16653 = T₁₈₂).

The spelling of 166503 in words is "one hundred sixty-six thousand, five hundred three".