66818423992320 has 5824 divisors, whose sum is σ = 343071024113664. Its totient is φ = 12016555130880.

The previous prime is 66818423992297. The next prime is 66818423992321. The reversal of 66818423992320 is 2329932481866.

It is a happy number.

66818423992320 is a `hidden beast` number, since 6 + 6 + 8 + 1 + 8 + 4 + 2 + 399 + 232 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (5824).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (66818423992321) by changing a digit.

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 447 ways as a sum of consecutive naturals, for example, 254062448509 + ... + 254062448771.

Almost surely, 2^{66818423992320} is an apocalyptic number.

66818423992320 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 66818423992320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171535512056832).

66818423992320 is an abundant number, since it is smaller than the sum of its proper divisors (276252600121344).

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

66818423992320 is a wasteful number, since it uses less digits than its factorization.

66818423992320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358 (or 321 counting only the distinct ones).

The product of its (nonzero) digits is 53747712, while the sum is 63.

The spelling of 66818423992320 in words is "sixty-six trillion, eight hundred eighteen billion, four hundred twenty-three million, nine hundred ninety-two thousand, three hundred twenty".