243121457 has 2 divisors, whose sum is σ = 243121458. Its totient is φ = 243121456.

The previous prime is 243121453. The next prime is 243121507. The reversal of 243121457 is 754121342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 224880016 + 18241441 = 14996^2 + 4271^2 .

It is a cyclic number.

It is not a de Polignac number, because 243121457 - 2² = 243121453 is a prime.

It is not a weakly prime, because it can be changed into another prime (243121453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121560728 + 121560729.

It is an arithmetic number, because the mean of its divisors is an integer number (121560729).

Almost surely, 2^243121457 is an apocalyptic number.

It is an amenable number.

243121457 is a deficient number, since it is larger than the sum of its proper divisors (1).

243121457 is an equidigital number, since it uses as much as digits as its factorization.

243121457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 29.

The square root of 243121457 is about 15592.3525165384. The cubic root of 243121457 is about 624.1290969817.

Adding to 243121457 its reverse (754121342), we get a palindrome (997242799).

The spelling of 243121457 in words is "two hundred forty-three million, one hundred twenty-one thousand, four hundred fifty-seven".