21131102211 has 4 divisors (see below), whose sum is σ = 28174802952. Its totient is φ = 14087401472.

The previous prime is 21131102203. The next prime is 21131102243. The reversal of 21131102211 is 11220113112.

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

It is a cyclic number.

It is not a de Polignac number, because 21131102211 - 2³ = 21131102203 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21131107211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3521850366 + ... + 3521850371.

It is an arithmetic number, because the mean of its divisors is an integer number (7043700738).

Almost surely, 2^21131102211 is an apocalyptic number.

21131102211 is a deficient number, since it is larger than the sum of its proper divisors (7043700741).

21131102211 is an equidigital number, since it uses as much as digits as its factorization.

21131102211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7043700740.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21131102211 its reverse (11220113112), we get a palindrome (32351215323).

The spelling of 21131102211 in words is "twenty-one billion, one hundred thirty-one million, one hundred two thousand, two hundred eleven".