21011221011101 has 2 divisors, whose sum is σ = 21011221011102. Its totient is φ = 21011221011100.

The previous prime is 21011221011097. The next prime is 21011221011197. The reversal of 21011221011101 is 10111012211012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15618264480025 + 5392956531076 = 3951995^2 + 2322274^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011221011101 - 2² = 21011221011097 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011221001101) 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, 10505610505550 + 10505610505551.

It is an arithmetic number, because the mean of its divisors is an integer number (10505610505551).

Almost surely, 2^{21011221011101} is an apocalyptic number.

It is an amenable number.

21011221011101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011221011101 is an equidigital number, since it uses as much as digits as its factorization.

21011221011101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21011221011101 its reverse (10111012211012), we get a palindrome (31122233222113).

The spelling of 21011221011101 in words is "twenty-one trillion, eleven billion, two hundred twenty-one million, eleven thousand, one hundred one".