681841844 has 6 divisors (see below), whose sum is σ = 1193223234. Its totient is φ = 340920920.

The previous prime is 681841837. The next prime is 681841889. The reversal of 681841844 is 448148186.

It can be written as a sum of positive squares in only one way, i.e., 658435600 + 23406244 = 25660^2 + 4838^2 .

It is a junction number, because it is equal to n+sod(n) for n = 681841795 and 681841804.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85230227 + ... + 85230234.

It is an arithmetic number, because the mean of its divisors is an integer number (198870539).

Almost surely, 2^681841844 is an apocalyptic number.

It is an amenable number.

681841844 is a deficient number, since it is larger than the sum of its proper divisors (511381390).

681841844 is a wasteful number, since it uses less digits than its factorization.

681841844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170460465 (or 170460463 counting only the distinct ones).

The product of its digits is 196608, while the sum is 44.

The square root of 681841844 is about 26112.1014857096. The cubic root of 681841844 is about 880.1591671461.

The spelling of 681841844 in words is "six hundred eighty-one million, eight hundred forty-one thousand, eight hundred forty-four".