660505849 has 2 divisors, whose sum is σ = 660505850. Its totient is φ = 660505848.

The previous prime is 660505847. The next prime is 660505889. The reversal of 660505849 is 948505066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 365765625 + 294740224 = 19125^2 + 17168^2 .

It is a cyclic number.

It is not a de Polignac number, because 660505849 - 2¹ = 660505847 is a prime.

Together with 660505847, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (660505847) 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, 330252924 + 330252925.

It is an arithmetic number, because the mean of its divisors is an integer number (330252925).

Almost surely, 2^660505849 is an apocalyptic number.

It is an amenable number.

660505849 is a deficient number, since it is larger than the sum of its proper divisors (1).

660505849 is an equidigital number, since it uses as much as digits as its factorization.

660505849 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 259200, while the sum is 43.

The square root of 660505849 is about 25700.3083444538. The cubic root of 660505849 is about 870.8811476007.

The spelling of 660505849 in words is "six hundred sixty million, five hundred five thousand, eight hundred forty-nine".