21204111113 has 4 divisors (see below), whose sum is σ = 21391758228. Its totient is φ = 21016464000.

The previous prime is 21204111091. The next prime is 21204111121. The reversal of 21204111113 is 31111140212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4939700089 + 16264411024 = 70283^2 + 127532^2 .

It is a cyclic number.

It is not a de Polignac number, because 21204111113 - 2²² = 21199916809 is a prime.

It is a super-2 number, since 2×21204111113² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21204111091 and 21204111100.

It is not an unprimeable number, because it can be changed into a prime (21204111413) 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, 93823388 + ... + 93823613.

It is an arithmetic number, because the mean of its divisors is an integer number (5347939557).

Almost surely, 2^21204111113 is an apocalyptic number.

It is an amenable number.

21204111113 is a deficient number, since it is larger than the sum of its proper divisors (187647115).

21204111113 is a wasteful number, since it uses less digits than its factorization.

21204111113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187647114.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21204111113 its reverse (31111140212), we get a palindrome (52315251325).

The spelling of 21204111113 in words is "twenty-one billion, two hundred four million, one hundred eleven thousand, one hundred thirteen".