66205856720 has 80 divisors (see below), whose sum is σ = 163030190400. Its totient is φ = 24917379072.

The previous prime is 66205856719. The next prime is 66205856779. The reversal of 66205856720 is 2765850266.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 8595431 + ... + 8603129.

It is an arithmetic number, because the mean of its divisors is an integer number (2037877380).

Almost surely, 2^66205856720 is an apocalyptic number.

It is an amenable number.

66205856720 is an abundant number, since it is smaller than the sum of its proper divisors (96824333680).

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

66205856720 is a wasteful number, since it uses less digits than its factorization.

66205856720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14052 (or 14046 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 47.

The spelling of 66205856720 in words is "sixty-six billion, two hundred five million, eight hundred fifty-six thousand, seven hundred twenty".