66969685440 has 560 divisors, whose sum is σ = 275596941312. Its totient is φ = 15119529984.

The previous prime is 66969685421. The next prime is 66969685441. The reversal of 66969685440 is 4458696966.

It is a tau number, because it is divible by the number of its divisors (560).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66969685441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 15057297 + ... + 15061743.

Almost surely, 2^66969685440 is an apocalyptic number.

66969685440 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 66969685440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137798470656).

66969685440 is an abundant number, since it is smaller than the sum of its proper divisors (208627255872).

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

66969685440 is a wasteful number, since it uses less digits than its factorization.

66969685440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4566 (or 4547 counting only the distinct ones).

The product of its (nonzero) digits is 67184640, while the sum is 63.

The spelling of 66969685440 in words is "sixty-six billion, nine hundred sixty-nine million, six hundred eighty-five thousand, four hundred forty".