684788720 has 120 divisors (see below), whose sum is σ = 2020571568. Its totient is φ = 213427200.

The previous prime is 684788707. The next prime is 684788743. The reversal of 684788720 is 27887486.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 35180 + ... + 51060.

Almost surely, 2^684788720 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 684788720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1010285784).

684788720 is an abundant number, since it is smaller than the sum of its proper divisors (1335782848).

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

684788720 is a wasteful number, since it uses less digits than its factorization.

684788720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15919 (or 15906 counting only the distinct ones).

The product of its (nonzero) digits is 1204224, while the sum is 50.

The square root of 684788720 is about 26168.4680483975. The cubic root of 684788720 is about 881.4253416337.

The spelling of 684788720 in words is "six hundred eighty-four million, seven hundred eighty-eight thousand, seven hundred twenty".