21113120205 has 40 divisors (see below), whose sum is σ = 38488744800. Its totient is φ = 11069465184.

The previous prime is 21113120143. The next prime is 21113120209. The reversal of 21113120205 is 50202131112.

It is not a de Polignac number, because 21113120205 - 2¹⁴ = 21113103821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113120209) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 417895 + ... + 465684.

It is an arithmetic number, because the mean of its divisors is an integer number (962218620).

Almost surely, 2^21113120205 is an apocalyptic number.

It is an amenable number.

21113120205 is a deficient number, since it is larger than the sum of its proper divisors (17375624595).

21113120205 is an equidigital number, since it uses as much as digits as its factorization.

21113120205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883655 (or 883646 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

Adding to 21113120205 its reverse (50202131112), we get a palindrome (71315251317).

The spelling of 21113120205 in words is "twenty-one billion, one hundred thirteen million, one hundred twenty thousand, two hundred five".