243957841 has 2 divisors, whose sum is σ = 243957842. Its totient is φ = 243957840.

The previous prime is 243957839. The next prime is 243957893. The reversal of 243957841 is 148759342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 216090000 + 27867841 = 14700^2 + 5279^2 .

It is a cyclic number.

It is not a de Polignac number, because 243957841 - 2¹ = 243957839 is a prime.

Together with 243957839, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (243957821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121978920 + 121978921.

It is an arithmetic number, because the mean of its divisors is an integer number (121978921).

Almost surely, 2^243957841 is an apocalyptic number.

It is an amenable number.

243957841 is a deficient number, since it is larger than the sum of its proper divisors (1).

243957841 is an equidigital number, since it uses as much as digits as its factorization.

243957841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 43.

The square root of 243957841 is about 15619.1498168114. The cubic root of 243957841 is about 624.8439853783.

The spelling of 243957841 in words is "two hundred forty-three million, nine hundred fifty-seven thousand, eight hundred forty-one".