21111020113 has 8 divisors (see below), whose sum is σ = 21193731432. Its totient is φ = 21028356096.

The previous prime is 21111020111. The next prime is 21111020123. The reversal of 21111020113 is 31102011112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5762783569 + 15348236544 = 75913^2 + 123888^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21111020113 - 2¹ = 21111020111 is a prime.

It is a super-3 number, since 3×21111020113³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111020093 and 21111020102.

It is not an unprimeable number, because it can be changed into a prime (21111020111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1075281 + ... + 1094737.

It is an arithmetic number, because the mean of its divisors is an integer number (2649216429).

Almost surely, 2^21111020113 is an apocalyptic number.

It is an amenable number.

21111020113 is a deficient number, since it is larger than the sum of its proper divisors (82711319).

21111020113 is a wasteful number, since it uses less digits than its factorization.

21111020113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23651.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 21111020113 its reverse (31102011112), we get a palindrome (52213031225).

Subtracting 21111020113 from its reverse (31102011112), we obtain a palindrome (9990990999).

The spelling of 21111020113 in words is "twenty-one billion, one hundred eleven million, twenty thousand, one hundred thirteen".