681381944 has 16 divisors (see below), whose sum is σ = 1277974320. Its totient is φ = 340588800.

The previous prime is 681381931. The next prime is 681381991. The reversal of 681381944 is 449183186.

It is a junction number, because it is equal to n+sod(n) for n = 681381895 and 681381904.

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 in 3 ways as a sum of consecutive naturals, for example, 20744 + ... + 42344.

It is an arithmetic number, because the mean of its divisors is an integer number (79873395).

Almost surely, 2^681381944 is an apocalyptic number.

It is an amenable number.

681381944 is a deficient number, since it is larger than the sum of its proper divisors (596592376).

681381944 is a wasteful number, since it uses less digits than its factorization.

681381944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25550 (or 25546 counting only the distinct ones).

The product of its digits is 165888, while the sum is 44.

The square root of 681381944 is about 26103.2937385304. The cubic root of 681381944 is about 879.9612345182.

The spelling of 681381944 in words is "six hundred eighty-one million, three hundred eighty-one thousand, nine hundred forty-four".