68131317640 has 128 divisors (see below), whose sum is σ = 160516224000. Its totient is φ = 25996723200.

The previous prime is 68131317619. The next prime is 68131317643. The reversal of 68131317640 is 4671313186.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 68131317593 and 68131317602.

It is not an unprimeable number, because it can be changed into a prime (68131317643) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28517566 + ... + 28519954.

It is an arithmetic number, because the mean of its divisors is an integer number (1254033000).

Almost surely, 2^68131317640 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 68131317640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80258112000).

68131317640 is an abundant number, since it is smaller than the sum of its proper divisors (92384906360).

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

68131317640 is a wasteful number, since it uses less digits than its factorization.

68131317640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2751 (or 2747 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 40.

The spelling of 68131317640 in words is "sixty-eight billion, one hundred thirty-one million, three hundred seventeen thousand, six hundred forty".