243566489 has 2 divisors, whose sum is σ = 243566490. Its totient is φ = 243566488.

The previous prime is 243566443. The next prime is 243566501. The reversal of 243566489 is 984665342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 203775625 + 39790864 = 14275^2 + 6308^2 .

It is a cyclic number.

It is not a de Polignac number, because 243566489 - 2¹⁶ = 243500953 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (243566689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121783244 + 121783245.

It is an arithmetic number, because the mean of its divisors is an integer number (121783245).

Almost surely, 2^243566489 is an apocalyptic number.

It is an amenable number.

243566489 is a deficient number, since it is larger than the sum of its proper divisors (1).

243566489 is an equidigital number, since it uses as much as digits as its factorization.

243566489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1244160, while the sum is 47.

The square root of 243566489 is about 15606.6168338945. The cubic root of 243566489 is about 624.5096860615.

The spelling of 243566489 in words is "two hundred forty-three million, five hundred sixty-six thousand, four hundred eighty-nine".