21021111210211 has 16 divisors (see below), whose sum is σ = 24257311211520. Its totient is φ = 17843327510400.

The previous prime is 21021111210139. The next prime is 21021111210247. The reversal of 21021111210211 is 11201211112012.

It is not a de Polignac number, because 21021111210211 - 2⁷ = 21021111210083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021111210271) 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, 2911971 + ... + 7107868.

It is an arithmetic number, because the mean of its divisors is an integer number (1516081950720).

Almost surely, 2^{21021111210211} is an apocalyptic number.

21021111210211 is a deficient number, since it is larger than the sum of its proper divisors (3236200001309).

21021111210211 is a wasteful number, since it uses less digits than its factorization.

21021111210211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10022754.

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

Adding to 21021111210211 its reverse (11201211112012), we get a palindrome (32222322322223).

The spelling of 21021111210211 in words is "twenty-one trillion, twenty-one billion, one hundred eleven million, two hundred ten thousand, two hundred eleven".