243120443021 has 2 divisors, whose sum is σ = 243120443022. Its totient is φ = 243120443020.

The previous prime is 243120443017. The next prime is 243120443057. The reversal of 243120443021 is 120344021342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 173180822500 + 69939620521 = 416150^2 + 264461^2 .

It is a cyclic number.

It is not a de Polignac number, because 243120443021 - 2² = 243120443017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243120443821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121560221510 + 121560221511.

It is an arithmetic number, because the mean of its divisors is an integer number (121560221511).

Almost surely, 2^243120443021 is an apocalyptic number.

It is an amenable number.

243120443021 is a deficient number, since it is larger than the sum of its proper divisors (1).

243120443021 is an equidigital number, since it uses as much as digits as its factorization.

243120443021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 243120443021 its reverse (120344021342), we get a palindrome (363464464363).

The spelling of 243120443021 in words is "two hundred forty-three billion, one hundred twenty million, four hundred forty-three thousand, twenty-one".