243440137 has 2 divisors, whose sum is σ = 243440138. Its totient is φ = 243440136.

The previous prime is 243440111. The next prime is 243440143. The reversal of 243440137 is 731044342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 198133776 + 45306361 = 14076^2 + 6731^2 .

It is a cyclic number.

It is not a de Polignac number, because 243440137 - 2²³ = 235051529 is a prime.

It is not a weakly prime, because it can be changed into another prime (243440107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121720068 + 121720069.

It is an arithmetic number, because the mean of its divisors is an integer number (121720069).

Almost surely, 2^243440137 is an apocalyptic number.

It is an amenable number.

243440137 is a deficient number, since it is larger than the sum of its proper divisors (1).

243440137 is an equidigital number, since it uses as much as digits as its factorization.

243440137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 28.

The square root of 243440137 is about 15602.5682821771. The cubic root of 243440137 is about 624.4016776393.

Adding to 243440137 its reverse (731044342), we get a palindrome (974484479).

The spelling of 243440137 in words is "two hundred forty-three million, four hundred forty thousand, one hundred thirty-seven".