243505312357 has 2 divisors, whose sum is σ = 243505312358. Its totient is φ = 243505312356.

The previous prime is 243505312333. The next prime is 243505312373. The reversal of 243505312357 is 753213505342.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 238247467236 + 5257845121 = 488106^2 + 72511^2 .

It is a cyclic number.

It is not a de Polignac number, because 243505312357 - 2⁷ = 243505312229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243505312327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121752656178 + 121752656179.

It is an arithmetic number, because the mean of its divisors is an integer number (121752656179).

Almost surely, 2^243505312357 is an apocalyptic number.

It is an amenable number.

243505312357 is a deficient number, since it is larger than the sum of its proper divisors (1).

243505312357 is an equidigital number, since it uses as much as digits as its factorization.

243505312357 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 378000, while the sum is 40.

Adding to 243505312357 its reverse (753213505342), we get a palindrome (996718817699).

The spelling of 243505312357 in words is "two hundred forty-three billion, five hundred five million, three hundred twelve thousand, three hundred fifty-seven".