688173544656 has 480 divisors, whose sum is σ = 2158901821440. Its totient is φ = 203314406400.

The previous prime is 688173544651. The next prime is 688173544661. The reversal of 688173544656 is 656445371886.

688173544656 is a `hidden beast` number, since 6 + 8 + 81 + 7 + 3 + 544 + 6 + 5 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (688173544651) and next prime (688173544661).

It is a junction number, because it is equal to n+sod(n) for n = 688173544593 and 688173544602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688173544651) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 995909271 + ... + 995909961.

It is an arithmetic number, because the mean of its divisors is an integer number (4497712128).

Almost surely, 2^688173544656 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 688173544656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1079450910720).

688173544656 is an abundant number, since it is smaller than the sum of its proper divisors (1470728276784).

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

688173544656 is a wasteful number, since it uses less digits than its factorization.

688173544656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 975 (or 966 counting only the distinct ones).

The product of its digits is 116121600, while the sum is 63.

The spelling of 688173544656 in words is "six hundred eighty-eight billion, one hundred seventy-three million, five hundred forty-four thousand, six hundred fifty-six".