686790 has 48 divisors (see below), whose sum is σ = 1926288. Its totient is φ = 168768.

The previous prime is 686789. The next prime is 686797. The reversal of 686790 is 97686.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686797) 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 23 ways as a sum of consecutive naturals, for example, 877 + ... + 1463.

It is an arithmetic number, because the mean of its divisors is an integer number (40131).

2⁶⁸⁶⁷⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686790, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (963144).

686790 is an abundant number, since it is smaller than the sum of its proper divisors (1239498).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686790 is a wasteful number, since it uses less digits than its factorization.

686790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 613 (or 610 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 686790 is about 828.7279408829. The cubic root of 686790 is about 88.2283155265.

The spelling of 686790 in words is "six hundred eighty-six thousand, seven hundred ninety".