66561801750764 has 12 divisors (see below), whose sum is σ = 121547637979824. Its totient is φ = 31833905185104.

The previous prime is 66561801750709. The next prime is 66561801750811. The reversal of 66561801750764 is 46705710816566.

It is a junction number, because it is equal to n+sod(n) for n = 66561801750697 and 66561801750706.

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 3 ways as a sum of consecutive naturals, for example, 361748922467 + ... + 361748922650.

It is an arithmetic number, because the mean of its divisors is an integer number (10128969831652).

Almost surely, 2^{66561801750764} is an apocalyptic number.

It is an amenable number.

66561801750764 is a deficient number, since it is larger than the sum of its proper divisors (54985836229060).

66561801750764 is a wasteful number, since it uses less digits than its factorization.

66561801750764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723497845144 (or 723497845142 counting only the distinct ones).

The product of its (nonzero) digits is 50803200, while the sum is 62.

The spelling of 66561801750764 in words is "sixty-six trillion, five hundred sixty-one billion, eight hundred one million, seven hundred fifty thousand, seven hundred sixty-four".