16660003 has 4 divisors (see below), whose sum is σ = 16681960. Its totient is φ = 16638048.

The previous prime is 16659997. The next prime is 16660013. The reversal of 16660003 is 30006661.

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

It is a cyclic number.

It is not a de Polignac number, because 16660003 - 2⁵ = 16659971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16660013) 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, 9798 + ... + 11371.

It is an arithmetic number, because the mean of its divisors is an integer number (4170490).

Almost surely, 2^16660003 is an apocalyptic number.

16660003 is a deficient number, since it is larger than the sum of its proper divisors (21957).

16660003 is an equidigital number, since it uses as much as digits as its factorization.

16660003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21956.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 16660003 is about 4081.6666938887. Note that the first 4 decimals coincide. The cubic root of 16660003 is about 255.4024300557.

Adding to 16660003 its reverse (30006661), we get a palindrome (46666664).

The spelling of 16660003 in words is "sixteen million, six hundred sixty thousand, three".