681899744868 has 12 divisors (see below), whose sum is σ = 1591099404720. Its totient is φ = 227299914952.

The previous prime is 681899744863. The next prime is 681899744873. The reversal of 681899744868 is 868447998186.

It is an interprime number because it is at equal distance from previous prime (681899744863) and next prime (681899744873).

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 681899744793 and 681899744802.

It is not an unprimeable number, because it can be changed into a prime (681899744861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28412489358 + ... + 28412489381.

It is an arithmetic number, because the mean of its divisors is an integer number (132591617060).

Almost surely, 2^681899744868 is an apocalyptic number.

It is an amenable number.

681899744868 is an abundant number, since it is smaller than the sum of its proper divisors (909199659852).

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

681899744868 is a wasteful number, since it uses less digits than its factorization.

681899744868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56824978746 (or 56824978744 counting only the distinct ones).

The product of its digits is 1337720832, while the sum is 78.

The spelling of 681899744868 in words is "six hundred eighty-one billion, eight hundred ninety-nine million, seven hundred forty-four thousand, eight hundred sixty-eight".