66638321149 has 2 divisors, whose sum is σ = 66638321150. Its totient is φ = 66638321148.

The previous prime is 66638321143. The next prime is 66638321179. The reversal of 66638321149 is 94112383666.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55927520100 + 10710801049 = 236490^2 + 103493^2 .

It is a cyclic number.

It is not a de Polignac number, because 66638321149 - 2¹¹ = 66638319101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66638321143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33319160574 + 33319160575.

It is an arithmetic number, because the mean of its divisors is an integer number (33319160575).

Almost surely, 2^66638321149 is an apocalyptic number.

It is an amenable number.

66638321149 is a deficient number, since it is larger than the sum of its proper divisors (1).

66638321149 is an equidigital number, since it uses as much as digits as its factorization.

66638321149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1119744, while the sum is 49.

The spelling of 66638321149 in words is "sixty-six billion, six hundred thirty-eight million, three hundred twenty-one thousand, one hundred forty-nine".