21221210211 has 32 divisors (see below), whose sum is σ = 30781658880. Its totient is φ = 12954464256.

The previous prime is 21221210191. The next prime is 21221210237. The reversal of 21221210211 is 11201212212.

It is not a de Polignac number, because 21221210211 - 2⁶ = 21221210147 is a prime.

It is a super-3 number, since 3×21221210211³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21221210261) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 255520 + ... + 328226.

It is an arithmetic number, because the mean of its divisors is an integer number (961926840).

Almost surely, 2^21221210211 is an apocalyptic number.

21221210211 is a deficient number, since it is larger than the sum of its proper divisors (9560448669).

21221210211 is a wasteful number, since it uses less digits than its factorization.

21221210211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72883.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21221210211 its reverse (11201212212), we get a palindrome (32422422423).

The spelling of 21221210211 in words is "twenty-one billion, two hundred twenty-one million, two hundred ten thousand, two hundred eleven".