684684 has 144 divisors (see below), whose sum is σ = 2446080. Its totient is φ = 155520.

The previous prime is 684683. The next prime is 684713. The reversal of 684684 is 486486.

684684 = T₂₀₇ + T₂₀₈ + ... + T₂₃₄.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (684683) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 36027 + ... + 36045.

2⁶⁸⁴⁶⁸⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1223040).

684684 is an abundant number, since it is smaller than the sum of its proper divisors (1761396).

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

684684 is a wasteful number, since it uses less digits than its factorization.

684684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60 (or 55 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 684684 is about 827.4563432593. The cubic root of 684684 is about 88.1380409251.

The spelling of 684684 in words is "six hundred eighty-four thousand, six hundred eighty-four".