686434390656 has 384 divisors, whose sum is σ = 2330162419200. Its totient is φ = 174868512768.

The previous prime is 686434390643. The next prime is 686434390679. The reversal of 686434390656 is 656093434686.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×686434390656² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 686434390656.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14736555 + ... + 14783061.

It is an arithmetic number, because the mean of its divisors is an integer number (6068131300).

Almost surely, 2^686434390656 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 686434390656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1165081209600).

686434390656 is an abundant number, since it is smaller than the sum of its proper divisors (1643728028544).

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

686434390656 is a wasteful number, since it uses less digits than its factorization.

686434390656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46584 (or 46555 counting only the distinct ones).

The product of its (nonzero) digits is 67184640, while the sum is 60.

The spelling of 686434390656 in words is "six hundred eighty-six billion, four hundred thirty-four million, three hundred ninety thousand, six hundred fifty-six".