686490 has 48 divisors (see below), whose sum is σ = 1920672. Its totient is φ = 156576.

The previous prime is 686479. The next prime is 686503. The reversal of 686490 is 94686.

It is a Curzon number.

It is a nialpdrome in base 15.

It is an unprimeable number.

686490 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 23 ways as a sum of consecutive naturals, for example, 1237 + ... + 1703.

It is an arithmetic number, because the mean of its divisors is an integer number (40014).

2⁶⁸⁶⁴⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (960336).

686490 is an abundant number, since it is smaller than the sum of its proper divisors (1234182).

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

686490 is a wasteful number, since it uses less digits than its factorization.

686490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491 (or 484 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 686490 is about 828.5469208198. The cubic root of 686490 is about 88.2154671791.

It can be divided in two parts, 686 and 490, that added together give a triangular number (1176 = T₄₈).

The spelling of 686490 in words is "six hundred eighty-six thousand, four hundred ninety".