686670 has 32 divisors (see below), whose sum is σ = 1686528. Its totient is φ = 178848.

The previous prime is 686669. The next prime is 686671. The reversal of 686670 is 76686.

It is an interprime number because it is at equal distance from previous prime (686669) and next prime (686671).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686671) 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 15 ways as a sum of consecutive naturals, for example, 1167 + ... + 1653.

It is an arithmetic number, because the mean of its divisors is an integer number (52704).

2⁶⁸⁶⁶⁷⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686670, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (843264).

686670 is an abundant number, since it is smaller than the sum of its proper divisors (999858).

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

686670 is a wasteful number, since it uses less digits than its factorization.

686670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544.

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 686670 is about 828.6555376029. The cubic root of 686670 is about 88.2231766366.

The spelling of 686670 in words is "six hundred eighty-six thousand, six hundred seventy".