66305639 has 2 divisors, whose sum is σ = 66305640. Its totient is φ = 66305638.

The previous prime is 66305633. The next prime is 66305677. The reversal of 66305639 is 93650366.

It is an a-pointer prime, because the next prime (66305677) can be obtained adding 66305639 to its sum of digits (38).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66305639 - 2²⁰ = 65257063 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66305633) 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, 33152819 + 33152820.

It is an arithmetic number, because the mean of its divisors is an integer number (33152820).

Almost surely, 2^66305639 is an apocalyptic number.

66305639 is a deficient number, since it is larger than the sum of its proper divisors (1).

66305639 is an equidigital number, since it uses as much as digits as its factorization.

66305639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 87480, while the sum is 38.

The square root of 66305639 is about 8142.8274573394. The cubic root of 66305639 is about 404.7468600502.

The spelling of 66305639 in words is "sixty-six million, three hundred five thousand, six hundred thirty-nine".