243242257 has 2 divisors, whose sum is σ = 243242258. Its totient is φ = 243242256.

The previous prime is 243242243. The next prime is 243242261. The reversal of 243242257 is 752242342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171060241 + 72182016 = 13079^2 + 8496^2 .

It is a cyclic number.

It is not a de Polignac number, because 243242257 - 2²⁷ = 109024529 is a prime.

It is not a weakly prime, because it can be changed into another prime (243042257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121621128 + 121621129.

It is an arithmetic number, because the mean of its divisors is an integer number (121621129).

Almost surely, 2^243242257 is an apocalyptic number.

It is an amenable number.

243242257 is a deficient number, since it is larger than the sum of its proper divisors (1).

243242257 is an equidigital number, since it uses as much as digits as its factorization.

243242257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26880, while the sum is 31.

The square root of 243242257 is about 15596.2257293231. The cubic root of 243242257 is about 624.2324504141.

Adding to 243242257 its reverse (752242342), we get a palindrome (995484599).

The spelling of 243242257 in words is "two hundred forty-three million, two hundred forty-two thousand, two hundred fifty-seven".