16662603665 has 4 divisors (see below), whose sum is σ = 19995124404. Its totient is φ = 13330082928.

The previous prime is 16662603623. The next prime is 16662603707. The reversal of 16662603665 is 56630626661.

16662603665 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 an interprime number because it is at equal distance from previous prime (16662603623) and next prime (16662603707).

It can be written as a sum of positive squares in 2 ways, for example, as 8005417729 + 8657185936 = 89473^2 + 93044^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16662603665 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1666260362 + ... + 1666260371.

It is an arithmetic number, because the mean of its divisors is an integer number (4998781101).

Almost surely, 2^16662603665 is an apocalyptic number.

It is an amenable number.

16662603665 is a deficient number, since it is larger than the sum of its proper divisors (3332520739).

16662603665 is an equidigital number, since it uses as much as digits as its factorization.

16662603665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3332520738.

The product of its (nonzero) digits is 1399680, while the sum is 47.

The spelling of 16662603665 in words is "sixteen billion, six hundred sixty-two million, six hundred three thousand, six hundred sixty-five".