66331513 has 2 divisors, whose sum is σ = 66331514. Its totient is φ = 66331512.

The previous prime is 66331511. The next prime is 66331543. The reversal of 66331513 is 31513366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62299449 + 4032064 = 7893^2 + 2008^2 .

It is a cyclic number.

It is not a de Polignac number, because 66331513 - 2¹ = 66331511 is a prime.

Together with 66331511, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66331511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33165756 + 33165757.

It is an arithmetic number, because the mean of its divisors is an integer number (33165757).

Almost surely, 2^66331513 is an apocalyptic number.

It is an amenable number.

66331513 is a deficient number, since it is larger than the sum of its proper divisors (1).

66331513 is an equidigital number, since it uses as much as digits as its factorization.

66331513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4860, while the sum is 28.

The square root of 66331513 is about 8144.4160625548. The cubic root of 66331513 is about 404.7995004114.

Adding to 66331513 its reverse (31513366), we get a palindrome (97844879).

The spelling of 66331513 in words is "sixty-six million, three hundred thirty-one thousand, five hundred thirteen".