66043613 has 2 divisors, whose sum is σ = 66043614. Its totient is φ = 66043612.

The previous prime is 66043591. The next prime is 66043619. The reversal of 66043613 is 31634066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65966884 + 76729 = 8122^2 + 277^2 .

It is a cyclic number.

It is not a de Polignac number, because 66043613 - 2⁸ = 66043357 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66043619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33021806 + 33021807.

It is an arithmetic number, because the mean of its divisors is an integer number (33021807).

Almost surely, 2^66043613 is an apocalyptic number.

It is an amenable number.

66043613 is a deficient number, since it is larger than the sum of its proper divisors (1).

66043613 is an equidigital number, since it uses as much as digits as its factorization.

66043613 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 29.

The square root of 66043613 is about 8126.7221559495. The cubic root of 66043613 is about 404.2129979172.

Adding to 66043613 its reverse (31634066), we get a palindrome (97677679).

The spelling of 66043613 in words is "sixty-six million, forty-three thousand, six hundred thirteen".