21111211113 has 16 divisors (see below), whose sum is σ = 29129767680. Its totient is φ = 13583759616.

The previous prime is 21111211111. The next prime is 21111211123. The reversal of 21111211113 is 31111211112.

It is not a de Polignac number, because 21111211113 - 2¹ = 21111211111 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21111211092 and 21111211101.

It is not an unprimeable number, because it can be changed into a prime (21111211111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 196881 + ... + 284577.

It is an arithmetic number, because the mean of its divisors is an integer number (1820610480).

Almost surely, 2^21111211113 is an apocalyptic number.

It is an amenable number.

21111211113 is a deficient number, since it is larger than the sum of its proper divisors (8018556567).

21111211113 is a wasteful number, since it uses less digits than its factorization.

21111211113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90496.

The product of its digits is 12, while the sum is 15.

Adding to 21111211113 its reverse (31111211112), we get a palindrome (52222422225).

Subtracting 21111211113 from its reverse (31111211112), we obtain a palindrome (9999999999).

The spelling of 21111211113 in words is "twenty-one billion, one hundred eleven million, two hundred eleven thousand, one hundred thirteen".