681847644 has 12 divisors (see below), whose sum is σ = 1590977864. Its totient is φ = 227282544.

The previous prime is 681847643. The next prime is 681847669. The reversal of 681847644 is 446748186.

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 = 681847593 and 681847602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681847643) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 28410307 + ... + 28410330.

Almost surely, 2^681847644 is an apocalyptic number.

It is an amenable number.

681847644 is an abundant number, since it is smaller than the sum of its proper divisors (909130220).

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

681847644 is a wasteful number, since it uses less digits than its factorization.

681847644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56820644 (or 56820642 counting only the distinct ones).

The product of its digits is 1032192, while the sum is 48.

The square root of 681847644 is about 26112.2125450909. The cubic root of 681847644 is about 880.1616627926.

The spelling of 681847644 in words is "six hundred eighty-one million, eight hundred forty-seven thousand, six hundred forty-four".