686782656 has 168 divisors, whose sum is σ = 2288682240. Its totient is φ = 192830976.

The previous prime is 686782637. The next prime is 686782667. The reversal of 686782656 is 656287686.

686782656 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (168).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 236445 + ... + 239331.

Almost surely, 2^686782656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686782656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1144341120).

686782656 is an abundant number, since it is smaller than the sum of its proper divisors (1601899584).

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

686782656 is a wasteful number, since it uses less digits than its factorization.

686782656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2971 (or 2958 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 54.

The square root of 686782656 is about 26206.5384207835. The cubic root of 686782656 is about 882.2800104364.

The spelling of 686782656 in words is "six hundred eighty-six million, seven hundred eighty-two thousand, six hundred fifty-six".