685728520 has 32 divisors (see below), whose sum is σ = 1543797720. Its totient is φ = 274129920.

The previous prime is 685728481. The next prime is 685728521. The reversal of 685728520 is 25827586.

It can be written as a sum of positive squares in 4 ways, for example, as 521939716 + 163788804 = 22846^2 + 12798^2 .

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (685728521) 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, 82474 + ... + 90406.

Almost surely, 2^685728520 is an apocalyptic number.

It is an amenable number.

685728520 is an abundant number, since it is smaller than the sum of its proper divisors (858069200).

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

685728520 is a wasteful number, since it uses less digits than its factorization.

685728520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10105 (or 10101 counting only the distinct ones).

The product of its (nonzero) digits is 268800, while the sum is 43.

The square root of 685728520 is about 26186.4186172909. The cubic root of 685728520 is about 881.8283782948.

The spelling of 685728520 in words is "six hundred eighty-five million, seven hundred twenty-eight thousand, five hundred twenty".