66068640 has 288 divisors, whose sum is σ = 254270016. Its totient is φ = 15482880.

The previous prime is 66068623. The next prime is 66068659. The reversal of 66068640 is 4686066.

66068640 is a `hidden beast` number, since 6 + 6 + 0 + 6 + 8 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 66068595 and 66068604.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 681072 + ... + 681168.

It is an arithmetic number, because the mean of its divisors is an integer number (882882).

Almost surely, 2^66068640 is an apocalyptic number.

66068640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66068640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127135008).

66068640 is an abundant number, since it is smaller than the sum of its proper divisors (188201376).

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

66068640 is a wasteful number, since it uses less digits than its factorization.

66068640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 66068640 is about 8128.2618068072. The cubic root of 66068640 is about 404.2640498443.

The spelling of 66068640 in words is "sixty-six million, sixty-eight thousand, six hundred forty".