243011221 has 2 divisors, whose sum is σ = 243011222. Its totient is φ = 243011220.

The previous prime is 243011183. The next prime is 243011267. The reversal of 243011221 is 122110342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 228342321 + 14668900 = 15111^2 + 3830^2 .

It is a cyclic number.

It is not a de Polignac number, because 243011221 - 2¹³ = 243003029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 243011195 and 243011204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243011621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121505610 + 121505611.

It is an arithmetic number, because the mean of its divisors is an integer number (121505611).

Almost surely, 2^243011221 is an apocalyptic number.

It is an amenable number.

243011221 is a deficient number, since it is larger than the sum of its proper divisors (1).

243011221 is an equidigital number, since it uses as much as digits as its factorization.

243011221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 243011221 is about 15588.8171777079. The cubic root of 243011221 is about 624.0347519614.

Adding to 243011221 its reverse (122110342), we get a palindrome (365121563).

The spelling of 243011221 in words is "two hundred forty-three million, eleven thousand, two hundred twenty-one".