681959 has 4 divisors (see below), whose sum is σ = 684816. Its totient is φ = 679104.

The previous prime is 681949. The next prime is 681971. The reversal of 681959 is 959186.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 959186 = 2 ⋅479593.

It is a cyclic number.

It is not a de Polignac number, because 681959 - 2⁴ = 681943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 681959.

It is not an unprimeable number, because it can be changed into a prime (681949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1034 + ... + 1559.

It is an arithmetic number, because the mean of its divisors is an integer number (171204).

2⁶⁸¹⁹⁵⁹ is an apocalyptic number.

681959 is a deficient number, since it is larger than the sum of its proper divisors (2857).

681959 is a wasteful number, since it uses less digits than its factorization.

681959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2856.

The product of its digits is 19440, while the sum is 38.

The square root of 681959 is about 825.8080890861. The cubic root of 681959 is about 88.0209574741.

The spelling of 681959 in words is "six hundred eighty-one thousand, nine hundred fifty-nine".