65640647 has 2 divisors, whose sum is σ = 65640648. Its totient is φ = 65640646.

The previous prime is 65640629. The next prime is 65640691. The reversal of 65640647 is 74604656.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 65640647 - 2¹⁸ = 65378503 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 65640647.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65340647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32820323 + 32820324.

It is an arithmetic number, because the mean of its divisors is an integer number (32820324).

Almost surely, 2^65640647 is an apocalyptic number.

65640647 is a deficient number, since it is larger than the sum of its proper divisors (1).

65640647 is an equidigital number, since it uses as much as digits as its factorization.

65640647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 38.

The square root of 65640647 is about 8101.8915692571. The cubic root of 65640647 is about 403.3892165053.

The spelling of 65640647 in words is "sixty-five million, six hundred forty thousand, six hundred forty-seven".