66650197920 has 48 divisors (see below), whose sum is σ = 209948124960. Its totient is φ = 17773385984.

The previous prime is 66650197897. The next prime is 66650197949. The reversal of 66650197920 is 2979105666.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 69426810 + ... + 69427769.

It is an arithmetic number, because the mean of its divisors is an integer number (4373919270).

Almost surely, 2^66650197920 is an apocalyptic number.

66650197920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66650197920 is an abundant number, since it is smaller than the sum of its proper divisors (143297927040).

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

66650197920 is a wasteful number, since it uses less digits than its factorization.

66650197920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138854597 (or 138854589 counting only the distinct ones).

The product of its (nonzero) digits is 1224720, while the sum is 51.

The spelling of 66650197920 in words is "sixty-six billion, six hundred fifty million, one hundred ninety-seven thousand, nine hundred twenty".