20243542415221 has 2 divisors, whose sum is σ = 20243542415222. Its totient is φ = 20243542415220.

The previous prime is 20243542415207. The next prime is 20243542415273. The reversal of 20243542415221 is 12251424534202.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13317755422500 + 6925786992721 = 3649350^2 + 2631689^2 .

It is a cyclic number.

It is not a de Polignac number, because 20243542415221 - 2⁵ = 20243542415189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20243542415021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10121771207610 + 10121771207611.

It is an arithmetic number, because the mean of its divisors is an integer number (10121771207611).

Almost surely, 2^{20243542415221} is an apocalyptic number.

It is an amenable number.

20243542415221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20243542415221 is an equidigital number, since it uses as much as digits as its factorization.

20243542415221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 153600, while the sum is 37.

Adding to 20243542415221 its reverse (12251424534202), we get a palindrome (32494966949423).

The spelling of 20243542415221 in words is "twenty trillion, two hundred forty-three billion, five hundred forty-two million, four hundred fifteen thousand, two hundred twenty-one".