66608424221 has 2 divisors, whose sum is σ = 66608424222. Its totient is φ = 66608424220.

The previous prime is 66608424193. The next prime is 66608424263. The reversal of 66608424221 is 12242480666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38380728100 + 28227696121 = 195910^2 + 168011^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66608424221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66608424721) by changing a digit.

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 as a sum of consecutive naturals, namely, 33304212110 + 33304212111.

It is an arithmetic number, because the mean of its divisors is an integer number (33304212111).

Almost surely, 2^66608424221 is an apocalyptic number.

It is an amenable number.

66608424221 is a deficient number, since it is larger than the sum of its proper divisors (1).

66608424221 is an equidigital number, since it uses as much as digits as its factorization.

66608424221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 221184, while the sum is 41.

The spelling of 66608424221 in words is "sixty-six billion, six hundred eight million, four hundred twenty-four thousand, two hundred twenty-one".