668835538867 has 4 divisors (see below), whose sum is σ = 668838355960. Its totient is φ = 668832721776.

The previous prime is 668835538859. The next prime is 668835538871. The reversal of 668835538867 is 768835538866.

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 668835538867 - 2³ = 668835538859 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 668835538867.

It is not an unprimeable number, because it can be changed into a prime (668835538067) 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, 1015938 + ... + 1539415.

It is an arithmetic number, because the mean of its divisors is an integer number (167209588990).

Almost surely, 2^668835538867 is an apocalyptic number.

668835538867 is a deficient number, since it is larger than the sum of its proper divisors (2817093).

668835538867 is a wasteful number, since it uses less digits than its factorization.

668835538867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2817092.

The product of its digits is 1393459200, while the sum is 73.

Subtracting 668835538867 from its reverse (768835538866), we obtain a palindrome (99999999999).

The spelling of 668835538867 in words is "six hundred sixty-eight billion, eight hundred thirty-five million, five hundred thirty-eight thousand, eight hundred sixty-seven".