21011101101211 has 6 divisors (see below), whose sum is σ = 22751665689660. Its totient is φ = 19394862554808.

The previous prime is 21011101101157. The next prime is 21011101101257. The reversal of 21011101101211 is 11210110111012.

It is not a de Polignac number, because 21011101101211 - 2¹⁵ = 21011101068443 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21011101101191 and 21011101101200.

It is not an unprimeable number, because it can be changed into a prime (21011101104211) 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 in 5 ways as a sum of consecutive naturals, for example, 62163020841 + ... + 62163021178.

It is an arithmetic number, because the mean of its divisors is an integer number (3791944281610).

Almost surely, 2^{21011101101211} is an apocalyptic number.

21011101101211 is a deficient number, since it is larger than the sum of its proper divisors (1740564588449).

21011101101211 is a wasteful number, since it uses less digits than its factorization.

21011101101211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124326042045 (or 124326042032 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 21011101101211 its reverse (11210110111012), we get a palindrome (32221211212223).

The spelling of 21011101101211 in words is "twenty-one trillion, eleven billion, one hundred one million, one hundred one thousand, two hundred eleven".