21131211311 has 16 divisors (see below), whose sum is σ = 24988953600. Its totient is φ = 17483530848.

The previous prime is 21131211307. The next prime is 21131211313. The reversal of 21131211311 is 11311213112.

It is not a de Polignac number, because 21131211311 - 2² = 21131211307 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21131211311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131211313) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 992900 + ... + 1013958.

It is an arithmetic number, because the mean of its divisors is an integer number (1561809600).

Almost surely, 2^21131211311 is an apocalyptic number.

21131211311 is a deficient number, since it is larger than the sum of its proper divisors (3857742289).

21131211311 is a wasteful number, since it uses less digits than its factorization.

21131211311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26038.

The product of its digits is 36, while the sum is 17.

Adding to 21131211311 its reverse (11311213112), we get a palindrome (32442424423).

The spelling of 21131211311 in words is "twenty-one billion, one hundred thirty-one million, two hundred eleven thousand, three hundred eleven".