66442939 has 2 divisors, whose sum is σ = 66442940. Its totient is φ = 66442938.

The previous prime is 66442933. The next prime is 66442993. The reversal of 66442939 is 93924466.

Together with next prime (66442993) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66442939 - 2⁵ = 66442907 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66442895 and 66442904.

It is not a weakly prime, because it can be changed into another prime (66442933) 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, 33221469 + 33221470.

It is an arithmetic number, because the mean of its divisors is an integer number (33221470).

Almost surely, 2^66442939 is an apocalyptic number.

66442939 is a deficient number, since it is larger than the sum of its proper divisors (1).

66442939 is an equidigital number, since it uses as much as digits as its factorization.

66442939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 43.

The square root of 66442939 is about 8151.2538299332. The cubic root of 66442939 is about 405.0260390716.

The spelling of 66442939 in words is "sixty-six million, four hundred forty-two thousand, nine hundred thirty-nine".