21221212020211 has 4 divisors (see below), whose sum is σ = 24252813737392. Its totient is φ = 18189610303032.

The previous prime is 21221212020161. The next prime is 21221212020221. The reversal of 21221212020211 is 11202021212212.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21221212020211 - 2¹¹ = 21221212018163 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221212020221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1515800858580 + ... + 1515800858593.

It is an arithmetic number, because the mean of its divisors is an integer number (6063203434348).

Almost surely, 2^{21221212020211} is an apocalyptic number.

21221212020211 is a deficient number, since it is larger than the sum of its proper divisors (3031601717181).

21221212020211 is an equidigital number, since it uses as much as digits as its factorization.

21221212020211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3031601717180.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21221212020211 its reverse (11202021212212), we get a palindrome (32423233232423).

The spelling of 21221212020211 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twelve million, twenty thousand, two hundred eleven".