66140647 has 2 divisors, whose sum is σ = 66140648. Its totient is φ = 66140646.

The previous prime is 66140623. The next prime is 66140687. The reversal of 66140647 is 74604166.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66140647 - 2⁷ = 66140519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66140687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33070323 + 33070324.

It is an arithmetic number, because the mean of its divisors is an integer number (33070324).

Almost surely, 2^66140647 is an apocalyptic number.

66140647 is a deficient number, since it is larger than the sum of its proper divisors (1).

66140647 is an equidigital number, since it uses as much as digits as its factorization.

66140647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 66140647 is about 8132.6900223727. The cubic root of 66140647 is about 404.4108631806.

The spelling of 66140647 in words is "sixty-six million, one hundred forty thousand, six hundred forty-seven".