686822656 has 72 divisors (see below), whose sum is σ = 1508177664. Its totient is φ = 310179840.

The previous prime is 686822641. The next prime is 686822687. The reversal of 686822656 is 656228686.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154221 + ... + 158611.

It is an arithmetic number, because the mean of its divisors is an integer number (20946912).

Almost surely, 2^686822656 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 686822656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (754088832).

686822656 is an abundant number, since it is smaller than the sum of its proper divisors (821355008).

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

686822656 is a wasteful number, since it uses less digits than its factorization.

686822656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4467 (or 4453 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 49.

The square root of 686822656 is about 26207.3015779954. The cubic root of 686822656 is about 882.2971388612.

The spelling of 686822656 in words is "six hundred eighty-six million, eight hundred twenty-two thousand, six hundred fifty-six".