243655121 has 2 divisors, whose sum is σ = 243655122. Its totient is φ = 243655120.

The previous prime is 243655099. The next prime is 243655193. The reversal of 243655121 is 121556342.

243655121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130530625 + 113124496 = 11425^2 + 10636^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243655121 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (243655021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121827560 + 121827561.

It is an arithmetic number, because the mean of its divisors is an integer number (121827561).

Almost surely, 2^243655121 is an apocalyptic number.

It is an amenable number.

243655121 is a deficient number, since it is larger than the sum of its proper divisors (1).

243655121 is an equidigital number, since it uses as much as digits as its factorization.

243655121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7200, while the sum is 29.

The square root of 243655121 is about 15609.4561404297. The cubic root of 243655121 is about 624.5854283227.

The spelling of 243655121 in words is "two hundred forty-three million, six hundred fifty-five thousand, one hundred twenty-one".