660893647 has 2 divisors, whose sum is σ = 660893648. Its totient is φ = 660893646.

The previous prime is 660893627. The next prime is 660893671. The reversal of 660893647 is 746398066.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-660893647 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 660893647.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660893627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330446823 + 330446824.

It is an arithmetic number, because the mean of its divisors is an integer number (330446824).

Almost surely, 2^660893647 is an apocalyptic number.

660893647 is a deficient number, since it is larger than the sum of its proper divisors (1).

660893647 is an equidigital number, since it uses as much as digits as its factorization.

660893647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1306368, while the sum is 49.

The square root of 660893647 is about 25707.8518550267. The cubic root of 660893647 is about 871.0515522957.

The spelling of 660893647 in words is "six hundred sixty million, eight hundred ninety-three thousand, six hundred forty-seven".