68121661608 has 672 divisors, whose sum is σ = 261873531360. Its totient is φ = 16323068160.

The previous prime is 68121661607. The next prime is 68121661637. The reversal of 68121661608 is 80616612186.

68121661608 is a `hidden beast` number, since 6 + 8 + 1 + 21 + 6 + 616 + 0 + 8 = 666.

68121661608 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×68121661608² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (68121661603) by changing a digit.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 40863991 + ... + 40865657.

It is an arithmetic number, because the mean of its divisors is an integer number (389692755).

Almost surely, 2^68121661608 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 68121661608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130936765680).

68121661608 is an abundant number, since it is smaller than the sum of its proper divisors (193751869752).

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

68121661608 is a wasteful number, since it uses less digits than its factorization.

68121661608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1729 (or 1703 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The spelling of 68121661608 in words is "sixty-eight billion, one hundred twenty-one million, six hundred sixty-one thousand, six hundred eight".