20011001221121 has 4 divisors (see below), whose sum is σ = 20011012770372. Its totient is φ = 20010989671872.

The previous prime is 20011001221097. The next prime is 20011001221171. The reversal of 20011001221121 is 12112210011002.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 14127344580496 + 5883656640625 = 3758636^2 + 2425625^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20011001221121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20011001221096 and 20011001221105.

It is not an unprimeable number, because it can be changed into a prime (20011001221171) 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 in 3 ways as a sum of consecutive naturals, for example, 2590316 + ... + 6836061.

It is an arithmetic number, because the mean of its divisors is an integer number (5002753192593).

Almost surely, 2^{20011001221121} is an apocalyptic number.

It is an amenable number.

20011001221121 is a deficient number, since it is larger than the sum of its proper divisors (11549251).

20011001221121 is an equidigital number, since it uses as much as digits as its factorization.

20011001221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11549250.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 20011001221121 its reverse (12112210011002), we get a palindrome (32123211232123).

The spelling of 20011001221121 in words is "twenty trillion, eleven billion, one million, two hundred twenty-one thousand, one hundred twenty-one".