68386640 has 80 divisors (see below), whose sum is σ = 188023680. Its totient is φ = 22632960.

The previous prime is 68386639. The next prime is 68386663. The reversal of 68386640 is 4668386.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14135 + ... + 18345.

It is an arithmetic number, because the mean of its divisors is an integer number (2350296).

Almost surely, 2^68386640 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 68386640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94011840).

68386640 is an abundant number, since it is smaller than the sum of its proper divisors (119637040).

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

68386640 is a wasteful number, since it uses less digits than its factorization.

68386640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4260 (or 4254 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 41.

The square root of 68386640 is about 8269.6215149183. The cubic root of 68386640 is about 408.9376423086.

The spelling of 68386640 in words is "sixty-eight million, three hundred eighty-six thousand, six hundred forty".