66768768 has 144 divisors (see below), whose sum is σ = 211629600. Its totient is φ = 20190720.

The previous prime is 66768763. The next prime is 66768781. The reversal of 66768768 is 86786766.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66768763) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 139153 + ... + 139631.

It is an arithmetic number, because the mean of its divisors is an integer number (1469650).

Almost surely, 2^66768768 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 66768768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105814800).

66768768 is an abundant number, since it is smaller than the sum of its proper divisors (144860832).

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

66768768 is a wasteful number, since it uses less digits than its factorization.

66768768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521 (or 495 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 54.

The square root of 66768768 is about 8171.2158214063. The cubic root of 66768768 is about 405.6870277641.

The spelling of 66768768 in words is "sixty-six million, seven hundred sixty-eight thousand, seven hundred sixty-eight".