668486568565 has 8 divisors (see below), whose sum is σ = 829845395640. Its totient is φ = 516348245952.

The previous prime is 668486568553. The next prime is 668486568577. The reversal of 668486568565 is 565865684866.

It is an interprime number because it is at equal distance from previous prime (668486568553) and next prime (668486568577).

It can be written as a sum of positive squares in 4 ways, for example, as 92025649 + 668394542916 = 9593^2 + 817554^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 668486568565 - 2¹⁵ = 668486535797 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2305125954 + ... + 2305126243.

It is an arithmetic number, because the mean of its divisors is an integer number (103730674455).

Almost surely, 2^668486568565 is an apocalyptic number.

It is an amenable number.

668486568565 is a deficient number, since it is larger than the sum of its proper divisors (161358827075).

668486568565 is a wasteful number, since it uses less digits than its factorization.

668486568565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4610252231.

The product of its digits is 1990656000, while the sum is 73.

The spelling of 668486568565 in words is "six hundred sixty-eight billion, four hundred eighty-six million, five hundred sixty-eight thousand, five hundred sixty-five".