20211221121101 has 2 divisors, whose sum is σ = 20211221121102. Its totient is φ = 20211221121100.

The previous prime is 20211221121079. The next prime is 20211221121127. The reversal of 20211221121101 is 10112112211202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11207590755076 + 9003630366025 = 3347774^2 + 3000605^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211221121101 - 2¹⁸ = 20211220858957 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20211221121101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211221121601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105610560550 + 10105610560551.

It is an arithmetic number, because the mean of its divisors is an integer number (10105610560551).

Almost surely, 2^{20211221121101} is an apocalyptic number.

It is an amenable number.

20211221121101 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211221121101 is an equidigital number, since it uses as much as digits as its factorization.

20211221121101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 20211221121101 its reverse (10112112211202), we get a palindrome (30323333332303).

The spelling of 20211221121101 in words is "twenty trillion, two hundred eleven billion, two hundred twenty-one million, one hundred twenty-one thousand, one hundred one".