681719618 has 16 divisors (see below), whose sum is σ = 1088351640. Its totient is φ = 319143936.

The previous prime is 681719603. The next prime is 681719629. The reversal of 681719618 is 816917186.

It can be written as a sum of positive squares in 4 ways, for example, as 627151849 + 54567769 = 25043^2 + 7387^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45383 + ... + 58506.

Almost surely, 2^681719618 is an apocalyptic number.

681719618 is a deficient number, since it is larger than the sum of its proper divisors (406632022).

681719618 is a wasteful number, since it uses less digits than its factorization.

681719618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104101.

The product of its digits is 145152, while the sum is 47.

The square root of 681719618 is about 26109.7609717132. The cubic root of 681719618 is about 880.1065719761.

The spelling of 681719618 in words is "six hundred eighty-one million, seven hundred nineteen thousand, six hundred eighteen".