681845 has 16 divisors (see below), whose sum is σ = 870912. Its totient is φ = 511680.

The previous prime is 681841. The next prime is 681883. The reversal of 681845 is 548186.

It is not a de Polignac number, because 681845 - 2² = 681841 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 (681841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8174 + ... + 8256.

It is an arithmetic number, because the mean of its divisors is an integer number (54432).

2⁶⁸¹⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

681845 is a deficient number, since it is larger than the sum of its proper divisors (189067).

681845 is a wasteful number, since it uses less digits than its factorization.

681845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172.

The product of its digits is 7680, while the sum is 32.

The square root of 681845 is about 825.7390629006. The cubic root of 681845 is about 88.0160525124.

The spelling of 681845 in words is "six hundred eighty-one thousand, eight hundred forty-five".