863686656 has 156 divisors (see below), whose sum is σ = 2852040672. Its totient is φ = 246693888.

The previous prime is 863686643. The next prime is 863686657. The reversal of 863686656 is 656686368.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (863686657) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 256375 + ... + 259721.

It is an arithmetic number, because the mean of its divisors is an integer number (18282312).

Almost surely, 2^863686656 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 863686656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1426020336).

863686656 is an abundant number, since it is smaller than the sum of its proper divisors (1988354016).

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

863686656 is a wasteful number, since it uses less digits than its factorization.

863686656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3384 (or 3359 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 54.

The square root of 863686656 is about 29388.5463403687. The cubic root of 863686656 is about 952.3254777694.

The spelling of 863686656 in words is "eight hundred sixty-three million, six hundred eighty-six thousand, six hundred fifty-six".