660533989 has 2 divisors, whose sum is σ = 660533990. Its totient is φ = 660533988.

The previous prime is 660533983. The next prime is 660533999. The reversal of 660533989 is 989335066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 418202500 + 242331489 = 20450^2 + 15567^2 .

It is a cyclic number.

It is not a de Polignac number, because 660533989 - 2³ = 660533981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660533981) 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, 330266994 + 330266995.

It is an arithmetic number, because the mean of its divisors is an integer number (330266995).

Almost surely, 2^660533989 is an apocalyptic number.

It is an amenable number.

660533989 is a deficient number, since it is larger than the sum of its proper divisors (1).

660533989 is an equidigital number, since it uses as much as digits as its factorization.

660533989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1049760, while the sum is 49.

The square root of 660533989 is about 25700.8558028716. The cubic root of 660533989 is about 870.8935150145.

The spelling of 660533989 in words is "six hundred sixty million, five hundred thirty-three thousand, nine hundred eighty-nine".