665601716818 has 8 divisors (see below), whose sum is σ = 998409006000. Its totient is φ = 332798714820.

The previous prime is 665601716803. The next prime is 665601716837. The reversal of 665601716818 is 818617106566.

665601716818 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 650548 + ... + 1324543.

It is an arithmetic number, because the mean of its divisors is an integer number (124801125750).

Almost surely, 2^665601716818 is an apocalyptic number.

665601716818 is a deficient number, since it is larger than the sum of its proper divisors (332807289182).

665601716818 is a wasteful number, since it uses less digits than its factorization.

665601716818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2143592.

The product of its (nonzero) digits is 2903040, while the sum is 55.

The spelling of 665601716818 in words is "six hundred sixty-five billion, six hundred one million, seven hundred sixteen thousand, eight hundred eighteen".