243444342509 has 2 divisors, whose sum is σ = 243444342510. Its totient is φ = 243444342508.

The previous prime is 243444342437. The next prime is 243444342541. The reversal of 243444342509 is 905243444342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 238415405284 + 5028937225 = 488278^2 + 70915^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243444342509 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 243444342509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243444342409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121722171254 + 121722171255.

It is an arithmetic number, because the mean of its divisors is an integer number (121722171255).

Almost surely, 2^243444342509 is an apocalyptic number.

It is an amenable number.

243444342509 is a deficient number, since it is larger than the sum of its proper divisors (1).

243444342509 is an equidigital number, since it uses as much as digits as its factorization.

243444342509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1658880, while the sum is 44.

The spelling of 243444342509 in words is "two hundred forty-three billion, four hundred forty-four million, three hundred forty-two thousand, five hundred nine".