66446816413 has 2 divisors, whose sum is σ = 66446816414. Its totient is φ = 66446816412.

The previous prime is 66446816389. The next prime is 66446816417. The reversal of 66446816413 is 31461864466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64962794884 + 1484021529 = 254878^2 + 38523^2 .

It is a cyclic number.

It is not a de Polignac number, because 66446816413 - 2²¹ = 66444719261 is a prime.

It is a super-2 number, since 2×66446816413² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66446816417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33223408206 + 33223408207.

It is an arithmetic number, because the mean of its divisors is an integer number (33223408207).

Almost surely, 2^66446816413 is an apocalyptic number.

It is an amenable number.

66446816413 is a deficient number, since it is larger than the sum of its proper divisors (1).

66446816413 is an equidigital number, since it uses as much as digits as its factorization.

66446816413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1990656, while the sum is 49.

The spelling of 66446816413 in words is "sixty-six billion, four hundred forty-six million, eight hundred sixteen thousand, four hundred thirteen".