668807867 has 24 divisors (see below), whose sum is σ = 847919520. Its totient is φ = 516222720.

The previous prime is 668807861. The next prime is 668807891. The reversal of 668807867 is 768708866.

It is not a de Polignac number, because 668807867 - 2²⁰ = 667759291 is a prime.

It is a super-2 number, since 2×668807867² = 894607925922179378, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (668807861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41609 + ... + 55397.

It is an arithmetic number, because the mean of its divisors is an integer number (35329980).

Almost surely, 2^668807867 is an apocalyptic number.

668807867 is a deficient number, since it is larger than the sum of its proper divisors (179111653).

668807867 is a wasteful number, since it uses less digits than its factorization.

668807867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13863 (or 13850 counting only the distinct ones).

The product of its (nonzero) digits is 5419008, while the sum is 56.

The square root of 668807867 is about 25861.3199005774. The cubic root of 668807867 is about 874.5147206257.

Subtracting 668807867 from its reverse (768708866), we obtain a palindrome (99900999).

It can be divided in two parts, 66880 and 7867, that added together give a palindrome (74747).

The spelling of 668807867 in words is "six hundred sixty-eight million, eight hundred seven thousand, eight hundred sixty-seven".