66509240383800 has 768 divisors, whose sum is σ = 244407057840000. Its totient is φ = 16591918694400.

The previous prime is 66509240383769. The next prime is 66509240383801. The reversal of 66509240383800 is 838304290566.

66509240383800 is a `hidden beast` number, since 6 + 6 + 509 + 24 + 0 + 38 + 3 + 80 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66509240383801) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1396378386 + ... + 1396426014.

Almost surely, 2^{66509240383800} is an apocalyptic number.

66509240383800 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 66509240383800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122203528920000).

66509240383800 is an abundant number, since it is smaller than the sum of its proper divisors (177897817456200).

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

66509240383800 is a wasteful number, since it uses less digits than its factorization.

66509240383800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47961 (or 47946 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The spelling of 66509240383800 in words is "sixty-six trillion, five hundred nine billion, two hundred forty million, three hundred eighty-three thousand, eight hundred".