21131224113 has 4 divisors (see below), whose sum is σ = 28174965488. Its totient is φ = 14087482740.

The previous prime is 21131224097. The next prime is 21131224139. The reversal of 21131224113 is 31142213112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21131224113 - 2⁴ = 21131224097 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 21131224113.

It is not an unprimeable number, because it can be changed into a prime (21131224193) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3521870683 + ... + 3521870688.

It is an arithmetic number, because the mean of its divisors is an integer number (7043741372).

Almost surely, 2^21131224113 is an apocalyptic number.

It is an amenable number.

21131224113 is a deficient number, since it is larger than the sum of its proper divisors (7043741375).

21131224113 is an equidigital number, since it uses as much as digits as its factorization.

21131224113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7043741374.

The product of its digits is 288, while the sum is 21.

Adding to 21131224113 its reverse (31142213112), we get a palindrome (52273437225).

The spelling of 21131224113 in words is "twenty-one billion, one hundred thirty-one million, two hundred twenty-four thousand, one hundred thirteen".