243081389 has 2 divisors, whose sum is σ = 243081390. Its totient is φ = 243081388.

The previous prime is 243081367. The next prime is 243081409. The reversal of 243081389 is 983180342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 229280164 + 13801225 = 15142^2 + 3715^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243081389 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243081329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121540694 + 121540695.

It is an arithmetic number, because the mean of its divisors is an integer number (121540695).

Almost surely, 2^243081389 is an apocalyptic number.

It is an amenable number.

243081389 is a deficient number, since it is larger than the sum of its proper divisors (1).

243081389 is an equidigital number, since it uses as much as digits as its factorization.

243081389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 243081389 is about 15591.0676029578. The cubic root of 243081389 is about 624.0948082509.

The spelling of 243081389 in words is "two hundred forty-three million, eighty-one thousand, three hundred eighty-nine".