668447208 has 512 divisors, whose sum is σ = 2467584000. Its totient is φ = 164229120.

The previous prime is 668447177. The next prime is 668447239. The reversal of 668447208 is 802744866.

It is an interprime number because it is at equal distance from previous prime (668447177) and next prime (668447239).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 9976791 + ... + 9976857.

It is an arithmetic number, because the mean of its divisors is an integer number (4819500).

Almost surely, 2^668447208 is an apocalyptic number.

668447208 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668447208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1233792000).

668447208 is an abundant number, since it is smaller than the sum of its proper divisors (1799136792).

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

668447208 is a wasteful number, since it uses less digits than its factorization.

668447208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 45.

The square root of 668447208 is about 25854.3460176428. The cubic root of 668447208 is about 874.3574964405.

The spelling of 668447208 in words is "six hundred sixty-eight million, four hundred forty-seven thousand, two hundred eight".