668531135867 has 4 divisors (see below), whose sum is σ = 764035583856. Its totient is φ = 573026687880.

The previous prime is 668531135821. The next prime is 668531135869. The reversal of 668531135867 is 768531135866.

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 668531135867 - 2³² = 664236168571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668531135869) 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, 47752223984 + ... + 47752223997.

It is an arithmetic number, because the mean of its divisors is an integer number (191008895964).

Almost surely, 2^668531135867 is an apocalyptic number.

668531135867 is a deficient number, since it is larger than the sum of its proper divisors (95504447989).

668531135867 is an equidigital number, since it uses as much as digits as its factorization.

668531135867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95504447988.

The product of its digits is 21772800, while the sum is 59.

Subtracting 668531135867 from its reverse (768531135866), we obtain a palindrome (99999999999).

The spelling of 668531135867 in words is "six hundred sixty-eight billion, five hundred thirty-one million, one hundred thirty-five thousand, eight hundred sixty-seven".