681788 has 6 divisors (see below), whose sum is σ = 1193136. Its totient is φ = 340892.

The previous prime is 681787. The next prime is 681809. The reversal of 681788 is 887186.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681781) by changing a digit.

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, 85220 + ... + 85227.

It is an arithmetic number, because the mean of its divisors is an integer number (198856).

2⁶⁸¹⁷⁸⁸ is an apocalyptic number.

It is an amenable number.

681788 is a deficient number, since it is larger than the sum of its proper divisors (511348).

681788 is a wasteful number, since it uses less digits than its factorization.

681788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170451 (or 170449 counting only the distinct ones).

The product of its digits is 21504, while the sum is 38.

The square root of 681788 is about 825.7045476440. The cubic root of 681788 is about 88.0135998265.

It can be divided in two parts, 68178 and 8, that added together give a palindrome (68186).

The spelling of 681788 in words is "six hundred eighty-one thousand, seven hundred eighty-eight".