805681 has 8 divisors (see below), whose sum is σ = 864864. Its totient is φ = 747840.

The previous prime is 805639. The next prime is 805687. The reversal of 805681 is 186508.

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 805681 - 2¹⁵ = 772913 is a prime.

It is a super-2 number, since 2×805681² = 1298243747522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (805687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1126 + ... + 1696.

It is an arithmetic number, because the mean of its divisors is an integer number (108108).

2⁸⁰⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

805681 is a deficient number, since it is larger than the sum of its proper divisors (59183).

805681 is a wasteful number, since it uses less digits than its factorization.

805681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 805681 is about 897.5973484809. The cubic root of 805681 is about 93.0509991218.

The spelling of 805681 in words is "eight hundred five thousand, six hundred eighty-one".