243505652021 has 2 divisors, whose sum is σ = 243505652022. Its totient is φ = 243505652020.

The previous prime is 243505652017. The next prime is 243505652051. The reversal of 243505652021 is 120256505342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204602428900 + 38903223121 = 452330^2 + 197239^2 .

It is a cyclic number.

It is not a de Polignac number, because 243505652021 - 2² = 243505652017 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243505652051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121752826010 + 121752826011.

It is an arithmetic number, because the mean of its divisors is an integer number (121752826011).

Almost surely, 2^243505652021 is an apocalyptic number.

It is an amenable number.

243505652021 is a deficient number, since it is larger than the sum of its proper divisors (1).

243505652021 is an equidigital number, since it uses as much as digits as its factorization.

243505652021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72000, while the sum is 35.

The spelling of 243505652021 in words is "two hundred forty-three billion, five hundred five million, six hundred fifty-two thousand, twenty-one".