684781728 has 48 divisors (see below), whose sum is σ = 1835809920. Its totient is φ = 223402496.

The previous prime is 684781711. The next prime is 684781729. The reversal of 684781728 is 827187486.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-3 number, since 3×684781728³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (684781729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71373 + ... + 80396.

It is an arithmetic number, because the mean of its divisors is an integer number (38246040).

Almost surely, 2^684781728 is an apocalyptic number.

It is an amenable number.

684781728 is an abundant number, since it is smaller than the sum of its proper divisors (1151028192).

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

684781728 is a wasteful number, since it uses less digits than its factorization.

684781728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151829 (or 151821 counting only the distinct ones).

The product of its digits is 1204224, while the sum is 51.

The square root of 684781728 is about 26168.3344521580. The cubic root of 684781728 is about 881.4223417075.

The spelling of 684781728 in words is "six hundred eighty-four million, seven hundred eighty-one thousand, seven hundred twenty-eight".