21131222211 has 12 divisors (see below), whose sum is σ = 33297683640. Its totient is φ = 12806801280.

The previous prime is 21131222209. The next prime is 21131222213. The reversal of 21131222211 is 11222213112.

It is an interprime number because it is at equal distance from previous prime (21131222209) and next prime (21131222213).

It is not a de Polignac number, because 21131222211 - 2¹ = 21131222209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21131222213) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 106723246 + ... + 106723443.

It is an arithmetic number, because the mean of its divisors is an integer number (2774806970).

Almost surely, 2^21131222211 is an apocalyptic number.

21131222211 is a deficient number, since it is larger than the sum of its proper divisors (12166461429).

21131222211 is a wasteful number, since it uses less digits than its factorization.

21131222211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213446706 (or 213446703 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

Adding to 21131222211 its reverse (11222213112), we get a palindrome (32353435323).

Subtracting from 21131222211 its reverse (11222213112), we obtain a palindrome (9909009099).

It can be divided in two parts, 21131 and 222211, that added together give a palindrome (243342).

The spelling of 21131222211 in words is "twenty-one billion, one hundred thirty-one million, two hundred twenty-two thousand, two hundred eleven".