66516543061321 has 8 divisors (see below), whose sum is σ = 67164336105984. Its totient is φ = 65868788504640.

The previous prime is 66516543061313. The next prime is 66516543061361. The reversal of 66516543061321 is 12316034561566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66516543061321 - 2³ = 66516543061313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66516543061361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6142585 + ... + 13067686.

It is an arithmetic number, because the mean of its divisors is an integer number (8395542013248).

Almost surely, 2^{66516543061321} is an apocalyptic number.

It is an amenable number.

66516543061321 is a deficient number, since it is larger than the sum of its proper divisors (647793044663).

66516543061321 is a wasteful number, since it uses less digits than its factorization.

66516543061321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19243991.

The product of its (nonzero) digits is 2332800, while the sum is 49.

The spelling of 66516543061321 in words is "sixty-six trillion, five hundred sixteen billion, five hundred forty-three million, sixty-one thousand, three hundred twenty-one".