243969389 has 2 divisors, whose sum is σ = 243969390. Its totient is φ = 243969388.

The previous prime is 243969377. The next prime is 243969391. The reversal of 243969389 is 983969342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 180687364 + 63282025 = 13442^2 + 7955^2 .

It is a cyclic number.

It is not a de Polignac number, because 243969389 - 2⁸ = 243969133 is a prime.

Together with 243969391, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 243969389.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243969589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121984694 + 121984695.

It is an arithmetic number, because the mean of its divisors is an integer number (121984695).

Almost surely, 2^243969389 is an apocalyptic number.

It is an amenable number.

243969389 is a deficient number, since it is larger than the sum of its proper divisors (1).

243969389 is an equidigital number, since it uses as much as digits as its factorization.

243969389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2519424, while the sum is 53.

The square root of 243969389 is about 15619.5194868472. The cubic root of 243969389 is about 624.8538444377.

The spelling of 243969389 in words is "two hundred forty-three million, nine hundred sixty-nine thousand, three hundred eighty-nine".