68640768 has 252 divisors, whose sum is σ = 242796060. Its totient is φ = 18579456.

The previous prime is 68640739. The next prime is 68640769. The reversal of 68640768 is 86704686.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (252).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68640769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3612663 + ... + 3612681.

Almost surely, 2^68640768 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 68640768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121398030).

68640768 is an abundant number, since it is smaller than the sum of its proper divisors (174155292).

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

68640768 is a wasteful number, since it uses less digits than its factorization.

68640768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65 (or 31 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The square root of 68640768 is about 8284.9724199903. The cubic root of 68640768 is about 409.4435600496.

The spelling of 68640768 in words is "sixty-eight million, six hundred forty thousand, seven hundred sixty-eight".