21105110223 has 16 divisors (see below), whose sum is σ = 31269634560. Its totient is φ = 14068811448.

The previous prime is 21105110197. The next prime is 21105110233. The reversal of 21105110223 is 32201150112.

It is not a de Polignac number, because 21105110223 - 2⁸ = 21105109967 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21105110196 and 21105110205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21105110233) 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, 347386 + ... + 403592.

It is an arithmetic number, because the mean of its divisors is an integer number (1954352160).

Almost surely, 2^21105110223 is an apocalyptic number.

21105110223 is a deficient number, since it is larger than the sum of its proper divisors (10164524337).

21105110223 is a wasteful number, since it uses less digits than its factorization.

21105110223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70123 (or 70117 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

Adding to 21105110223 its reverse (32201150112), we get a palindrome (53306260335).

It can be divided in two parts, 21105 and 110223, that added together give a triangular number (131328 = T₅₁₂).

The spelling of 21105110223 in words is "twenty-one billion, one hundred five million, one hundred ten thousand, two hundred twenty-three".