685808640 has 528 divisors, whose sum is σ = 2744290080. Its totient is φ = 162201600.

The previous prime is 685808633. The next prime is 685808657. The reversal of 685808640 is 46808586.

685808640 is a `hidden beast` number, since 6 + 8 + 580 + 8 + 64 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (528).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16727020 + ... + 16727060.

Almost surely, 2^685808640 is an apocalyptic number.

685808640 is a gapful number since it is divisible by the number (60) 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 685808640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1372145040).

685808640 is an abundant number, since it is smaller than the sum of its proper divisors (2058481440).

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

685808640 is a wasteful number, since it uses less digits than its factorization.

685808640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97 (or 62 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The square root of 685808640 is about 26187.9483732499. The cubic root of 685808640 is about 881.8627210102.

The spelling of 685808640 in words is "six hundred eighty-five million, eight hundred eight thousand, six hundred forty".