668947806 has 12 divisors (see below), whose sum is σ = 1449386952. Its totient is φ = 222982596.

The previous prime is 668947787. The next prime is 668947813. The reversal of 668947806 is 608749866.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18581866 + ... + 18581901.

It is an arithmetic number, because the mean of its divisors is an integer number (120782246).

Almost surely, 2^668947806 is an apocalyptic number.

668947806 is an abundant number, since it is smaller than the sum of its proper divisors (780439146).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668947806 is a wasteful number, since it uses less digits than its factorization.

668947806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37163775 (or 37163772 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The square root of 668947806 is about 25864.0253247634. The cubic root of 668947806 is about 874.5757098311.

The spelling of 668947806 in words is "six hundred sixty-eight million, nine hundred forty-seven thousand, eight hundred six".