66740747221 has 2 divisors, whose sum is σ = 66740747222. Its totient is φ = 66740747220.

The previous prime is 66740747209. The next prime is 66740747263. The reversal of 66740747221 is 12274704766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39700562500 + 27040184721 = 199250^2 + 164439^2 .

It is a cyclic number.

It is not a de Polignac number, because 66740747221 - 2⁵ = 66740747189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66740757221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33370373610 + 33370373611.

It is an arithmetic number, because the mean of its divisors is an integer number (33370373611).

Almost surely, 2^66740747221 is an apocalyptic number.

It is an amenable number.

66740747221 is a deficient number, since it is larger than the sum of its proper divisors (1).

66740747221 is an equidigital number, since it uses as much as digits as its factorization.

66740747221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 790272, while the sum is 46.

The spelling of 66740747221 in words is "sixty-six billion, seven hundred forty million, seven hundred forty-seven thousand, two hundred twenty-one".