681908650 has 12 divisors (see below), whose sum is σ = 1268350182. Its totient is φ = 272763440.

The previous prime is 681908629. The next prime is 681908701. The reversal of 681908650 is 56809186.

It can be written as a sum of positive squares in 3 ways, for example, as 626450841 + 55457809 = 25029^2 + 7447^2 .

It is a junction number, because it is equal to n+sod(n) for n = 681908597 and 681908606.

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 in 5 ways as a sum of consecutive naturals, for example, 6819037 + ... + 6819136.

Almost surely, 2^681908650 is an apocalyptic number.

681908650 is a deficient number, since it is larger than the sum of its proper divisors (586441532).

681908650 is a wasteful number, since it uses less digits than its factorization.

681908650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13638185 (or 13638180 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 681908650 is about 26113.3806696873. The cubic root of 681908650 is about 880.1879118340.

The spelling of 681908650 in words is "six hundred eighty-one million, nine hundred eight thousand, six hundred fifty".