66511567668 has 144 divisors (see below), whose sum is σ = 195978652800. Its totient is φ = 17541328896.

The previous prime is 66511567651. The next prime is 66511567691. The reversal of 66511567668 is 86676511566.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 647796 + ... + 743412.

Almost surely, 2^66511567668 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 66511567668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97989326400).

66511567668 is an abundant number, since it is smaller than the sum of its proper divisors (129467085132).

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

66511567668 is a wasteful number, since it uses less digits than its factorization.

66511567668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95671 (or 95642 counting only the distinct ones).

The product of its digits is 10886400, while the sum is 57.

The spelling of 66511567668 in words is "sixty-six billion, five hundred eleven million, five hundred sixty-seven thousand, six hundred sixty-eight".