684880 has 40 divisors (see below), whose sum is σ = 1821312. Its totient is φ = 234624.

The previous prime is 684869. The next prime is 684889. The reversal of 684880 is 88486.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×684880² = 938121228800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684889) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52 + ... + 1171.

2⁶⁸⁴⁸⁸⁰ 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 684880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (910656).

684880 is an abundant number, since it is smaller than the sum of its proper divisors (1136432).

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

684880 is a wasteful number, since it uses less digits than its factorization.

684880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1243 (or 1237 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 34.

The square root of 684880 is about 827.5747700359. The cubic root of 684880 is about 88.1464503557.

The spelling of 684880 in words is "six hundred eighty-four thousand, eight hundred eighty".