681565 has 8 divisors (see below), whose sum is σ = 822528. Its totient is φ = 542160.

The previous prime is 681563. The next prime is 681589. The reversal of 681565 is 565186.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 681565 - 2¹ = 681563 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681563) 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 in 7 ways as a sum of consecutive naturals, for example, 1104 + ... + 1606.

It is an arithmetic number, because the mean of its divisors is an integer number (102816).

2⁶⁸¹⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

681565 is a deficient number, since it is larger than the sum of its proper divisors (140963).

681565 is a wasteful number, since it uses less digits than its factorization.

681565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779.

The product of its digits is 7200, while the sum is 31.

The square root of 681565 is about 825.5695004056. The cubic root of 681565 is about 88.0040029171.

The spelling of 681565 in words is "six hundred eighty-one thousand, five hundred sixty-five".