66856341769152 has 672 divisors, whose sum is σ = 206355294931968. Its totient is φ = 18953615966208.

The previous prime is 66856341769097. The next prime is 66856341769159. The reversal of 66856341769152 is 25196714365866.

It is a Harshad number since it is a multiple of its sum of digits (69).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66856341769159) 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 95 ways as a sum of consecutive naturals, for example, 24284903008 + ... + 24284905760.

It is an arithmetic number, because the mean of its divisors is an integer number (307076331744).

Almost surely, 2^{66856341769152} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66856341769152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103177647465984).

66856341769152 is an abundant number, since it is smaller than the sum of its proper divisors (139498953162816).

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

66856341769152 is a wasteful number, since it uses less digits than its factorization.

66856341769152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3365 (or 3326 counting only the distinct ones).

The product of its digits is 391910400, while the sum is 69.

The spelling of 66856341769152 in words is "sixty-six trillion, eight hundred fifty-six billion, three hundred forty-one million, seven hundred sixty-nine thousand, one hundred fifty-two".