66138028889 has 2 divisors, whose sum is σ = 66138028890. Its totient is φ = 66138028888.

The previous prime is 66138028829. The next prime is 66138028909. The reversal of 66138028889 is 98882083166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48925900864 + 17212128025 = 221192^2 + 131195^2 .

It is a cyclic number.

It is not a de Polignac number, because 66138028889 - 2²⁴ = 66121251673 is a prime.

It is not a weakly prime, because it can be changed into another prime (66138028829) 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, 33069014444 + 33069014445.

It is an arithmetic number, because the mean of its divisors is an integer number (33069014445).

Almost surely, 2^66138028889 is an apocalyptic number.

It is an amenable number.

66138028889 is a deficient number, since it is larger than the sum of its proper divisors (1).

66138028889 is an equidigital number, since it uses as much as digits as its factorization.

66138028889 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7962624, while the sum is 59.

The spelling of 66138028889 in words is "sixty-six billion, one hundred thirty-eight million, twenty-eight thousand, eight hundred eighty-nine".