684018 has 32 divisors (see below), whose sum is σ = 1555200. Its totient is φ = 222768.

The previous prime is 684017. The next prime is 684037. The reversal of 684018 is 810486.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 683982 and 684000.

It is not an unprimeable number, because it can be changed into a prime (684017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2743 + ... + 2981.

It is an arithmetic number, because the mean of its divisors is an integer number (48600).

2⁶⁸⁴⁰¹⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (777600).

684018 is an abundant number, since it is smaller than the sum of its proper divisors (871182).

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

684018 is a wasteful number, since it uses less digits than its factorization.

684018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 684018 is about 827.0538071976. The cubic root of 684018 is about 88.1094540255.

The spelling of 684018 in words is "six hundred eighty-four thousand, eighteen".