21211312113 has 6 divisors (see below), whose sum is σ = 30638561954. Its totient is φ = 14140874736.

The previous prime is 21211312099. The next prime is 21211312181. The reversal of 21211312113 is 31121311212.

It can be written as a sum of positive squares in only one way, i.e., 19106979984 + 2104332129 = 138228^2 + 45873^2 .

It is not a de Polignac number, because 21211312113 - 2⁵ = 21211312081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211312513) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1178406220 + ... + 1178406237.

Almost surely, 2^21211312113 is an apocalyptic number.

It is an amenable number.

21211312113 is a deficient number, since it is larger than the sum of its proper divisors (9427249841).

21211312113 is a wasteful number, since it uses less digits than its factorization.

21211312113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2356812463 (or 2356812460 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 21211312113 its reverse (31121311212), we get a palindrome (52332623325).

Subtracting 21211312113 from its reverse (31121311212), we obtain a palindrome (9909999099).

The spelling of 21211312113 in words is "twenty-one billion, two hundred eleven million, three hundred twelve thousand, one hundred thirteen".