20201243242421 has 2 divisors, whose sum is σ = 20201243242422. Its totient is φ = 20201243242420.

The previous prime is 20201243242373. The next prime is 20201243242447. The reversal of 20201243242421 is 12424234210202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20035345879396 + 165897363025 = 4476086^2 + 407305^2 .

It is a cyclic number.

It is not a de Polignac number, because 20201243242421 - 2¹⁸ = 20201242980277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20201243244421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10100621621210 + 10100621621211.

It is an arithmetic number, because the mean of its divisors is an integer number (10100621621211).

Almost surely, 2^{20201243242421} is an apocalyptic number.

It is an amenable number.

20201243242421 is a deficient number, since it is larger than the sum of its proper divisors (1).

20201243242421 is an equidigital number, since it uses as much as digits as its factorization.

20201243242421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12288, while the sum is 29.

Adding to 20201243242421 its reverse (12424234210202), we get a palindrome (32625477452623).

The spelling of 20201243242421 in words is "twenty trillion, two hundred one billion, two hundred forty-three million, two hundred forty-two thousand, four hundred twenty-one".