21211231311 has 6 divisors (see below), whose sum is σ = 30638445240. Its totient is φ = 14140820868.

The previous prime is 21211231259. The next prime is 21211231319. The reversal of 21211231311 is 11313211212.

21211231311 is a `hidden beast` number, since 2 + 121 + 1 + 231 + 311 = 666.

It is not a de Polignac number, because 21211231311 - 2²⁵ = 21177676879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211231319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1178401731 + ... + 1178401748.

It is an arithmetic number, because the mean of its divisors is an integer number (5106407540).

Almost surely, 2^21211231311 is an apocalyptic number.

21211231311 is a deficient number, since it is larger than the sum of its proper divisors (9427213929).

21211231311 is a wasteful number, since it uses less digits than its factorization.

21211231311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2356803485 (or 2356803482 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 21211231311 its reverse (11313211212), we get a palindrome (32524442523).

The spelling of 21211231311 in words is "twenty-one billion, two hundred eleven million, two hundred thirty-one thousand, three hundred eleven".