687843 has 12 divisors (see below), whose sum is σ = 1070160. Its totient is φ = 423216.

The previous prime is 687839. The next prime is 687847. The reversal of 687843 is 348786.

It is an interprime number because it is at equal distance from previous prime (687839) and next prime (687847).

It is not a de Polignac number, because 687843 - 2² = 687839 is a prime.

It is a super-3 number, since 3×687843³ = 976313333542998321, which contains 333 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

687843 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 687798 and 687807.

It is not an unprimeable number, because it can be changed into a prime (687847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2823 + ... + 3056.

It is an arithmetic number, because the mean of its divisors is an integer number (89180).

2⁶⁸⁷⁸⁴³ is an apocalyptic number.

687843 is a deficient number, since it is larger than the sum of its proper divisors (382317).

687843 is a wasteful number, since it uses less digits than its factorization.

687843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5898 (or 5895 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 687843 is about 829.3630085795. The cubic root of 687843 is about 88.2733836335.

The spelling of 687843 in words is "six hundred eighty-seven thousand, eight hundred forty-three".