681587 has 8 divisors (see below), whose sum is σ = 742800. Its totient is φ = 622944.

The previous prime is 681563. The next prime is 681589. The reversal of 681587 is 785186.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 681587 - 2⁶ = 681523 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 681587.

It is not an unprimeable number, because it can be changed into a prime (681589) 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, 68 + ... + 1169.

It is an arithmetic number, because the mean of its divisors is an integer number (92850).

2⁶⁸¹⁵⁸⁷ is an apocalyptic number.

681587 is a deficient number, since it is larger than the sum of its proper divisors (61213).

681587 is a wasteful number, since it uses less digits than its factorization.

681587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1285.

The product of its digits is 13440, while the sum is 35.

The square root of 681587 is about 825.5828244337. The cubic root of 681587 is about 88.0049497905.

The spelling of 681587 in words is "six hundred eighty-one thousand, five hundred eighty-seven".