243320571541 has 2 divisors, whose sum is σ = 243320571542. Its totient is φ = 243320571540.

The previous prime is 243320571521. The next prime is 243320571581. The reversal of 243320571541 is 145175023342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 242781867441 + 538704100 = 492729^2 + 23210^2 .

It is a cyclic number.

It is not a de Polignac number, because 243320571541 - 2¹⁷ = 243320440469 is a prime.

It is a super-2 number, since 2×243320571541² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 243320571541.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243320571521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121660285770 + 121660285771.

It is an arithmetic number, because the mean of its divisors is an integer number (121660285771).

Almost surely, 2^243320571541 is an apocalyptic number.

It is an amenable number.

243320571541 is a deficient number, since it is larger than the sum of its proper divisors (1).

243320571541 is an equidigital number, since it uses as much as digits as its factorization.

243320571541 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 100800, while the sum is 37.

Adding to 243320571541 its reverse (145175023342), we get a palindrome (388495594883).

The spelling of 243320571541 in words is "two hundred forty-three billion, three hundred twenty million, five hundred seventy-one thousand, five hundred forty-one".