668687746 has 8 divisors (see below), whose sum is σ = 1003233600. Its totient is φ = 334276548.

The previous prime is 668687699. The next prime is 668687759. The reversal of 668687746 is 647786866.

It is a happy number.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20166 + ... + 41761.

It is an arithmetic number, because the mean of its divisors is an integer number (125404200).

Almost surely, 2^668687746 is an apocalyptic number.

668687746 is a deficient number, since it is larger than the sum of its proper divisors (334545854).

668687746 is a wasteful number, since it uses less digits than its factorization.

668687746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67328.

The product of its digits is 16257024, while the sum is 58.

The square root of 668687746 is about 25858.9973896901. The cubic root of 668687746 is about 874.4623618554.

The spelling of 668687746 in words is "six hundred sixty-eight million, six hundred eighty-seven thousand, seven hundred forty-six".