66564743321 has 2 divisors, whose sum is σ = 66564743322. Its totient is φ = 66564743320.

The previous prime is 66564743303. The next prime is 66564743369. The reversal of 66564743321 is 12334746566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35045712025 + 31519031296 = 187205^2 + 177536^2 .

It is a cyclic number.

It is not a de Polignac number, because 66564743321 - 2⁶ = 66564743257 is a prime.

It is a super-2 number, since 2×66564743321² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66564743821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33282371660 + 33282371661.

It is an arithmetic number, because the mean of its divisors is an integer number (33282371661).

Almost surely, 2^66564743321 is an apocalyptic number.

It is an amenable number.

66564743321 is a deficient number, since it is larger than the sum of its proper divisors (1).

66564743321 is an equidigital number, since it uses as much as digits as its factorization.

66564743321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2177280, while the sum is 47.

The spelling of 66564743321 in words is "sixty-six billion, five hundred sixty-four million, seven hundred forty-three thousand, three hundred twenty-one".