66165643 has 2 divisors, whose sum is σ = 66165644. Its totient is φ = 66165642.

The previous prime is 66165637. The next prime is 66165653. The reversal of 66165643 is 34656166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66165643 - 2⁹ = 66165131 is a prime.

It is not a weakly prime, because it can be changed into another prime (66165653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33082821 + 33082822.

It is an arithmetic number, because the mean of its divisors is an integer number (33082822).

Almost surely, 2^66165643 is an apocalyptic number.

66165643 is a deficient number, since it is larger than the sum of its proper divisors (1).

66165643 is an equidigital number, since it uses as much as digits as its factorization.

66165643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77760, while the sum is 37.

The square root of 66165643 is about 8134.2266381015. The cubic root of 66165643 is about 404.4618020069.

The spelling of 66165643 in words is "sixty-six million, one hundred sixty-five thousand, six hundred forty-three".