681601808 has 30 divisors (see below), whose sum is σ = 1399169934. Its totient is φ = 320551168.

The previous prime is 681601793. The next prime is 681601829. The reversal of 681601808 is 808106186.

It can be written as a sum of positive squares in only one way, i.e., 641507584 + 40094224 = 25328^2 + 6332^2 .

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, 429785 + ... + 431367.

Almost surely, 2^681601808 is an apocalyptic number.

681601808 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

681601808 is an abundant number, since it is smaller than the sum of its proper divisors (717568126).

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

681601808 is an equidigital number, since it uses as much as digits as its factorization.

681601808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3191 (or 1602 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 681601808 is about 26107.5048214110. The cubic root of 681601808 is about 880.0558711083.

The spelling of 681601808 in words is "six hundred eighty-one million, six hundred one thousand, eight hundred eight".