21021211211 has 64 divisors (see below), whose sum is σ = 29497982976. Its totient is φ = 14452905600.

The previous prime is 21021211193. The next prime is 21021211213. The reversal of 21021211211 is 11211212012.

It is not a de Polignac number, because 21021211211 - 2¹⁰ = 21021210187 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21021211213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2017826 + ... + 2028216.

It is an arithmetic number, because the mean of its divisors is an integer number (460905984).

Almost surely, 2^21021211211 is an apocalyptic number.

21021211211 is a deficient number, since it is larger than the sum of its proper divisors (8476771765).

21021211211 is a wasteful number, since it uses less digits than its factorization.

21021211211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10512.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21021211211 its reverse (11211212012), we get a palindrome (32232423223).

It can be divided in two parts, 21021 and 211211, that added together give a palindrome (232232).

The spelling of 21021211211 in words is "twenty-one billion, twenty-one million, two hundred eleven thousand, two hundred eleven".