21211211113 has 4 divisors (see below), whose sum is σ = 21257024128. Its totient is φ = 21165398100.

The previous prime is 21211211111. The next prime is 21211211123. The reversal of 21211211113 is 31111211212.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 21211211113 - 2¹ = 21211211111 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211211111) 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, 22905813 + ... + 22906738.

It is an arithmetic number, because the mean of its divisors is an integer number (5314256032).

Almost surely, 2^21211211113 is an apocalyptic number.

It is an amenable number.

21211211113 is a deficient number, since it is larger than the sum of its proper divisors (45813015).

21211211113 is an equidigital number, since it uses as much as digits as its factorization.

21211211113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45813014.

The product of its digits is 24, while the sum is 16.

Adding to 21211211113 its reverse (31111211212), we get a palindrome (52322422325).

Subtracting 21211211113 from its reverse (31111211212), we obtain a palindrome (9900000099).

It can be divided in two parts, 21211 and 211113, that added together give a square (232324 = 482²).

The spelling of 21211211113 in words is "twenty-one billion, two hundred eleven million, two hundred eleven thousand, one hundred thirteen".