166220503 has 4 divisors (see below), whose sum is σ = 168324640. Its totient is φ = 164116368.

The previous prime is 166220491. The next prime is 166220513. The reversal of 166220503 is 305022661.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166220503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166220513) 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, 1051950 + ... + 1052107.

It is an arithmetic number, because the mean of its divisors is an integer number (42081160).

Almost surely, 2^166220503 is an apocalyptic number.

166220503 is a deficient number, since it is larger than the sum of its proper divisors (2104137).

166220503 is an equidigital number, since it uses as much as digits as its factorization.

166220503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2104136.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 166220503 is about 12892.6530628882. The cubic root of 166220503 is about 549.8297026479.

The spelling of 166220503 in words is "one hundred sixty-six million, two hundred twenty thousand, five hundred three".