681744 has 40 divisors (see below), whose sum is σ = 2013760. Its totient is φ = 194688.

The previous prime is 681731. The next prime is 681763. The reversal of 681744 is 447186.

It is a nude number because it is divisible by every one of its digits.

It is an Ulam number.

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, 679 + ... + 1350.

It is an arithmetic number, because the mean of its divisors is an integer number (50344).

2⁶⁸¹⁷⁴⁴ is an apocalyptic number.

It is an amenable number.

681744 is an abundant number, since it is smaller than the sum of its proper divisors (1332016).

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

681744 is a wasteful number, since it uses less digits than its factorization.

681744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2047 (or 2041 counting only the distinct ones).

The product of its digits is 5376, while the sum is 30.

The square root of 681744 is about 825.6779033013. The cubic root of 681744 is about 88.0117064316.

The spelling of 681744 in words is "six hundred eighty-one thousand, seven hundred forty-four".