20744543121121 has 4 divisors (see below), whose sum is σ = 21028714944772. Its totient is φ = 20460371297472.

The previous prime is 20744543121059. The next prime is 20744543121161. The reversal of 20744543121121 is 12112134544702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16835954810896 + 3908588310225 = 4103164^2 + 1977015^2 .

It is a cyclic number.

It is not a de Polignac number, because 20744543121121 - 2¹⁷ = 20744542990049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20744543121161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142085911716 + ... + 142085911861.

It is an arithmetic number, because the mean of its divisors is an integer number (5257178736193).

Almost surely, 2^{20744543121121} is an apocalyptic number.

It is an amenable number.

20744543121121 is a deficient number, since it is larger than the sum of its proper divisors (284171823651).

20744543121121 is an equidigital number, since it uses as much as digits as its factorization.

20744543121121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284171823650.

The product of its (nonzero) digits is 53760, while the sum is 37.

Adding to 20744543121121 its reverse (12112134544702), we get a palindrome (32856677665823).

The spelling of 20744543121121 in words is "twenty trillion, seven hundred forty-four billion, five hundred forty-three million, one hundred twenty-one thousand, one hundred twenty-one".