680891 has 8 divisors (see below), whose sum is σ = 719280. Its totient is φ = 643552.

The previous prime is 680881. The next prime is 680917. The reversal of 680891 is 198086.

680891 = 139² + 140² + ... + 167².

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 680891 - 2¹⁰ = 679867 is a prime.

It is a super-2 number, since 2×680891² = 927225107762, which contains 22 as substring.

It is an Ulam number.

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 680891.

It is not an unprimeable number, because it can be changed into a prime (680831) 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, 1316 + ... + 1758.

It is an arithmetic number, because the mean of its divisors is an integer number (89910).

2⁶⁸⁰⁸⁹¹ is an apocalyptic number.

680891 is a deficient number, since it is larger than the sum of its proper divisors (38389).

680891 is a wasteful number, since it uses less digits than its factorization.

680891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 680891 is about 825.1611963732. The cubic root of 680891 is about 87.9749842807.

The spelling of 680891 in words is "six hundred eighty thousand, eight hundred ninety-one".