66505545985 has 16 divisors (see below), whose sum is σ = 79926690816. Its totient is φ = 53124478848.

The previous prime is 66505545979. The next prime is 66505545989. The reversal of 66505545985 is 58954550566.

It is a cyclic number.

It is not a de Polignac number, because 66505545985 - 2⁷ = 66505545857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66505545989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15525654 + ... + 15529936.

It is an arithmetic number, because the mean of its divisors is an integer number (4995418176).

Almost surely, 2^66505545985 is an apocalyptic number.

It is an amenable number.

66505545985 is a deficient number, since it is larger than the sum of its proper divisors (13421144831).

66505545985 is a wasteful number, since it uses less digits than its factorization.

66505545985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8232.

The product of its (nonzero) digits is 32400000, while the sum is 58.

The spelling of 66505545985 in words is "sixty-six billion, five hundred five million, five hundred forty-five thousand, nine hundred eighty-five".