243256609 has 2 divisors, whose sum is σ = 243256610. Its totient is φ = 243256608.

The previous prime is 243256583. The next prime is 243256619. The reversal of 243256609 is 906652342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 130302225 + 112954384 = 11415^2 + 10628^2 .

It is a cyclic number.

It is not a de Polignac number, because 243256609 - 2⁵ = 243256577 is a prime.

It is not a weakly prime, because it can be changed into another prime (243256619) 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, 121628304 + 121628305.

It is an arithmetic number, because the mean of its divisors is an integer number (121628305).

Almost surely, 2^243256609 is an apocalyptic number.

It is an amenable number.

243256609 is a deficient number, since it is larger than the sum of its proper divisors (1).

243256609 is an equidigital number, since it uses as much as digits as its factorization.

243256609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 37.

The square root of 243256609 is about 15596.6858338559. The cubic root of 243256609 is about 624.2447273488.

The spelling of 243256609 in words is "two hundred forty-three million, two hundred fifty-six thousand, six hundred nine".