686442 has 8 divisors (see below), whose sum is σ = 1372896. Its totient is φ = 228812.

The previous prime is 686437. The next prime is 686449. The reversal of 686442 is 244686.

It is a sphenic number, since it is the product of 3 distinct primes.

686442 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (686449) by changing a digit.

686442 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 3 ways as a sum of consecutive naturals, for example, 57198 + ... + 57209.

It is an arithmetic number, because the mean of its divisors is an integer number (171612).

2⁶⁸⁶⁴⁴² is an apocalyptic number.

686442 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

686442 is a wasteful number, since it uses less digits than its factorization.

686442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114412.

The product of its digits is 9216, while the sum is 30.

The square root of 686442 is about 828.5179539394. The cubic root of 686442 is about 88.2134110962.

It can be divided in two parts, 686 and 442, that added together give a triangular number (1128 = T₄₇).

The spelling of 686442 in words is "six hundred eighty-six thousand, four hundred forty-two".