66281513 has 2 divisors, whose sum is σ = 66281514. Its totient is φ = 66281512.

The previous prime is 66281473. The next prime is 66281539. The reversal of 66281513 is 31518266.

It is a happy number.

66281513 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46895104 + 19386409 = 6848^2 + 4403^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66281513 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66281513.

It is not a weakly prime, because it can be changed into another prime (66281573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33140756 + 33140757.

It is an arithmetic number, because the mean of its divisors is an integer number (33140757).

Almost surely, 2^66281513 is an apocalyptic number.

It is an amenable number.

66281513 is a deficient number, since it is larger than the sum of its proper divisors (1).

66281513 is an equidigital number, since it uses as much as digits as its factorization.

66281513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 32.

The square root of 66281513 is about 8141.3458961034. The cubic root of 66281513 is about 404.6977636361.

Adding to 66281513 its reverse (31518266), we get a palindrome (97799779).

The spelling of 66281513 in words is "sixty-six million, two hundred eighty-one thousand, five hundred thirteen".