685767720 has 64 divisors (see below), whose sum is σ = 2244335040. Its totient is φ = 166246400.

The previous prime is 685767707. The next prime is 685767721. The reversal of 685767720 is 27767586.

It is a self number, because there is not a number n which added to its sum of digits gives 685767720.

It is not an unprimeable number, because it can be changed into a prime (685767721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 258441 + ... + 261080.

It is an arithmetic number, because the mean of its divisors is an integer number (35067735).

Almost surely, 2^685767720 is an apocalyptic number.

685767720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

685767720 is an abundant number, since it is smaller than the sum of its proper divisors (1558567320).

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

685767720 is a wasteful number, since it uses less digits than its factorization.

685767720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519546 (or 519542 counting only the distinct ones).

The product of its (nonzero) digits is 987840, while the sum is 48.

The square root of 685767720 is about 26187.1670861894. The cubic root of 685767720 is about 881.8451813554.

The spelling of 685767720 in words is "six hundred eighty-five million, seven hundred sixty-seven thousand, seven hundred twenty".