66838552323840 has 2304 divisors, whose sum is σ = 287773013606400. Its totient is φ = 14680112578560.

The previous prime is 66838552323827. The next prime is 66838552323857. The reversal of 66838552323840 is 4832325583866.

It is a happy number.

66838552323840 is a `hidden beast` number, since 6 + 6 + 8 + 3 + 8 + 5 + 523 + 23 + 84 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2304).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 13456521037 + ... + 13456526003.

It is an arithmetic number, because the mean of its divisors is an integer number (124901481600).

Almost surely, 2^{66838552323840} is an apocalyptic number.

66838552323840 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 66838552323840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143886506803200).

66838552323840 is an abundant number, since it is smaller than the sum of its proper divisors (220934461282560).

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

66838552323840 is a wasteful number, since it uses less digits than its factorization.

66838552323840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5062 (or 5030 counting only the distinct ones).

The product of its (nonzero) digits is 199065600, while the sum is 63.

The spelling of 66838552323840 in words is "sixty-six trillion, eight hundred thirty-eight billion, five hundred fifty-two million, three hundred twenty-three thousand, eight hundred forty".