68643617856 has 112 divisors (see below), whose sum is σ = 199691304960. Its totient is φ = 20637227520.

The previous prime is 68643617851. The next prime is 68643617857. The reversal of 68643617856 is 65871634686.

It is a self number, because there is not a number n which added to its sum of digits gives 68643617856.

It is not an unprimeable number, because it can be changed into a prime (68643617851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 140265 + ... + 396183.

It is an arithmetic number, because the mean of its divisors is an integer number (1782958080).

Almost surely, 2^68643617856 is an apocalyptic number.

68643617856 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 68643617856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99845652480).

68643617856 is an abundant number, since it is smaller than the sum of its proper divisors (131047687104).

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

68643617856 is a wasteful number, since it uses less digits than its factorization.

68643617856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256072 (or 256062 counting only the distinct ones).

The product of its digits is 34836480, while the sum is 60.

The spelling of 68643617856 in words is "sixty-eight billion, six hundred forty-three million, six hundred seventeen thousand, eight hundred fifty-six".