685728064 has 56 divisors (see below), whose sum is σ = 1557698688. Its totient is φ = 293399040.

The previous prime is 685728059. The next prime is 685728077. The reversal of 685728064 is 460827586.

It is a tau number, because it is divible by the number of its divisors (56).

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 7 ways as a sum of consecutive naturals, for example, 453069 + ... + 454579.

It is an arithmetic number, because the mean of its divisors is an integer number (27816048).

Almost surely, 2^685728064 is an apocalyptic number.

685728064 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685728064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (778849344).

685728064 is an abundant number, since it is smaller than the sum of its proper divisors (871970624).

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

685728064 is a wasteful number, since it uses less digits than its factorization.

685728064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2543 (or 2533 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 46.

The square root of 685728064 is about 26186.4099104860. The cubic root of 685728064 is about 881.8281828268.

It can be divided in two parts, 68572 and 8064, that added together give a triangular number (76636 = T₃₉₁).

The spelling of 685728064 in words is "six hundred eighty-five million, seven hundred twenty-eight thousand, sixty-four".