684320 has 96 divisors (see below), whose sum is σ = 2032128. Its totient is φ = 211968.

The previous prime is 684311. The next prime is 684329. The reversal of 684320 is 23486.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (684311) and next prime (684329).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 684320.

It is not an unprimeable number, because it can be changed into a prime (684329) by changing a digit.

684320 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 (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14537 + ... + 14583.

It is an arithmetic number, because the mean of its divisors is an integer number (21168).

2⁶⁸⁴³²⁰ 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 684320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1016064).

684320 is an abundant number, since it is smaller than the sum of its proper divisors (1347808).

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

684320 is a wasteful number, since it uses less digits than its factorization.

684320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 684320 is about 827.2363628371. The cubic root of 684320 is about 88.1224191522.

The spelling of 684320 in words is "six hundred eighty-four thousand, three hundred twenty".