66206866440 has 256 divisors, whose sum is σ = 233593113600. Its totient is φ = 14799744000.

The previous prime is 66206866393. The next prime is 66206866447. The reversal of 66206866440 is 4466860266.

It is a happy number.

It is a super-3 number, since 3×66206866440³ (a number of 33 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66206866440.

It is not an unprimeable number, because it can be changed into a prime (66206866447) 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 63 ways as a sum of consecutive naturals, for example, 24897831 + ... + 24900489.

It is an arithmetic number, because the mean of its divisors is an integer number (912473100).

Almost surely, 2^66206866440 is an apocalyptic number.

66206866440 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 66206866440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116796556800).

66206866440 is an abundant number, since it is smaller than the sum of its proper divisors (167386247160).

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

66206866440 is a wasteful number, since it uses less digits than its factorization.

66206866440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4148 (or 4144 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 48.

The spelling of 66206866440 in words is "sixty-six billion, two hundred six million, eight hundred sixty-six thousand, four hundred forty".