66106779648 has 768 divisors, whose sum is σ = 234823680000. Its totient is φ = 16387080192.

The previous prime is 66106779647. The next prime is 66106779679. The reversal of 66106779648 is 84697760166.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (768).

It is a junction number, because it is equal to n+sod(n) for n = 66106779591 and 66106779600.

It is not an unprimeable number, because it can be changed into a prime (66106779643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 520525761 + ... + 520525887.

It is an arithmetic number, because the mean of its divisors is an integer number (305760000).

Almost surely, 2^66106779648 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 66106779648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117411840000).

66106779648 is an abundant number, since it is smaller than the sum of its proper divisors (168716900352).

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

66106779648 is a wasteful number, since it uses less digits than its factorization.

66106779648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 18289152, while the sum is 60.

The spelling of 66106779648 in words is "sixty-six billion, one hundred six million, seven hundred seventy-nine thousand, six hundred forty-eight".