21011221112211 has 12 divisors (see below), whose sum is σ = 33108590843640. Its totient is φ = 12734073401280.

The previous prime is 21011221112197. The next prime is 21011221112251. The reversal of 21011221112211 is 11221112211012.

It is a happy number.

21011221112211 is a `hidden beast` number, since 210 + 1 + 1 + 221 + 11 + 221 + 1 = 666.

It is not a de Polignac number, because 21011221112211 - 2¹⁹ = 21011220587923 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21011221112251) 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 11 ways as a sum of consecutive naturals, for example, 106117278246 + ... + 106117278443.

It is an arithmetic number, because the mean of its divisors is an integer number (2759049236970).

Almost surely, 2^{21011221112211} is an apocalyptic number.

21011221112211 is a deficient number, since it is larger than the sum of its proper divisors (12097369731429).

21011221112211 is a wasteful number, since it uses less digits than its factorization.

21011221112211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212234556706 (or 212234556703 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21011221112211 its reverse (11221112211012), we get a palindrome (32232333323223).

The spelling of 21011221112211 in words is "twenty-one trillion, eleven billion, two hundred twenty-one million, one hundred twelve thousand, two hundred eleven".