681594 has 16 divisors (see below), whose sum is σ = 1392768. Its totient is φ = 222272.

The previous prime is 681589. The next prime is 681607. The reversal of 681594 is 495186.

It is a Curzon number.

It is an unprimeable number.

681594 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 7 ways as a sum of consecutive naturals, for example, 927 + ... + 1490.

It is an arithmetic number, because the mean of its divisors is an integer number (87048).

2⁶⁸¹⁵⁹⁴ is an apocalyptic number.

681594 is an abundant number, since it is smaller than the sum of its proper divisors (711174).

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

681594 is a wasteful number, since it uses less digits than its factorization.

681594 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2469.

The product of its digits is 8640, while the sum is 33.

The square root of 681594 is about 825.5870638521. The cubic root of 681594 is about 88.0052510641.

It can be divided in two parts, 681 and 594, that added together give a triangular number (1275 = T₅₀).

The spelling of 681594 in words is "six hundred eighty-one thousand, five hundred ninety-four".