21000212220211 has 16 divisors (see below), whose sum is σ = 24565293206784. Its totient is φ = 17576629316064.

The previous prime is 21000212220193. The next prime is 21000212220257. The reversal of 21000212220211 is 11202221200012.

It is a happy number.

It is not a de Polignac number, because 21000212220211 - 2²⁵ = 21000178665779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21000212220271) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8736505 + ... + 10877818.

It is an arithmetic number, because the mean of its divisors is an integer number (1535330825424).

Almost surely, 2^{21000212220211} is an apocalyptic number.

21000212220211 is a deficient number, since it is larger than the sum of its proper divisors (3565080986573).

21000212220211 is a wasteful number, since it uses less digits than its factorization.

21000212220211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19617930.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21000212220211 its reverse (11202221200012), we get a palindrome (32202433420223).

The spelling of 21000212220211 in words is "twenty-one trillion, two hundred twelve million, two hundred twenty thousand, two hundred eleven".