66664349 has 2 divisors, whose sum is σ = 66664350. Its totient is φ = 66664348.

The previous prime is 66664321. The next prime is 66664357. The reversal of 66664349 is 94346666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65723449 + 940900 = 8107^2 + 970^2 .

It is a cyclic number.

It is not a de Polignac number, because 66664349 - 2⁸ = 66664093 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66664049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33332174 + 33332175.

It is an arithmetic number, because the mean of its divisors is an integer number (33332175).

Almost surely, 2^66664349 is an apocalyptic number.

It is an amenable number.

66664349 is a deficient number, since it is larger than the sum of its proper divisors (1).

66664349 is an equidigital number, since it uses as much as digits as its factorization.

66664349 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 44.

The square root of 66664349 is about 8164.8238805255. The cubic root of 66664349 is about 405.4754341448.

The spelling of 66664349 in words is "sixty-six million, six hundred sixty-four thousand, three hundred forty-nine".