68643431808 has 128 divisors (see below), whose sum is σ = 209214109440. Its totient is φ = 19534080000.

The previous prime is 68643431807. The next prime is 68643431833. The reversal of 68643431808 is 80813434686.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×68643431808² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68643431807) 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, 623818 + ... + 725558.

It is an arithmetic number, because the mean of its divisors is an integer number (1634485230).

Almost surely, 2^68643431808 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 68643431808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104607054720).

68643431808 is an abundant number, since it is smaller than the sum of its proper divisors (140570677632).

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

68643431808 is a wasteful number, since it uses less digits than its factorization.

68643431808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102016 (or 102004 counting only the distinct ones).

The product of its (nonzero) digits is 2654208, while the sum is 51.

The spelling of 68643431808 in words is "sixty-eight billion, six hundred forty-three million, four hundred thirty-one thousand, eight hundred eight".