21113131424 has 96 divisors (see below), whose sum is σ = 51879647232. Its totient is φ = 8216928000.

The previous prime is 21113131421. The next prime is 21113131439. The reversal of 21113131424 is 42413131112.

It is a self number, because there is not a number n which added to its sum of digits gives 21113131424.

It is not an unprimeable number, because it can be changed into a prime (21113131421) 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, 2536229 + ... + 2544539.

It is an arithmetic number, because the mean of its divisors is an integer number (540412992).

Almost surely, 2^21113131424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21113131424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25939823616).

21113131424 is an abundant number, since it is smaller than the sum of its proper divisors (30766515808).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21113131424 is a wasteful number, since it uses less digits than its factorization.

21113131424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9370 (or 9362 counting only the distinct ones).

The product of its digits is 576, while the sum is 23.

Adding to 21113131424 its reverse (42413131112), we get a palindrome (63526262536).

The spelling of 21113131424 in words is "twenty-one billion, one hundred thirteen million, one hundred thirty-one thousand, four hundred twenty-four".