1681320208 has 10 divisors (see below), whose sum is σ = 3257557934. Its totient is φ = 840660096.

The previous prime is 1681320197. The next prime is 1681320229. The reversal of 1681320208 is 8020231861.

It can be written as a sum of positive squares in only one way, i.e., 1680344064 + 976144 = 40992^2 + 988^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1681320208.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52541241 + ... + 52541272.

Almost surely, 2^1681320208 is an apocalyptic number.

It is an amenable number.

1681320208 is a deficient number, since it is larger than the sum of its proper divisors (1576237726).

1681320208 is a wasteful number, since it uses less digits than its factorization.

1681320208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105082521 (or 105082515 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 1681320208 is about 41003.9047896661. The cubic root of 1681320208 is about 1189.0957063726.

The spelling of 1681320208 in words is "one billion, six hundred eighty-one million, three hundred twenty thousand, two hundred eight".