21101010111221 has 8 divisors (see below), whose sum is σ = 22018493917440. Its totient is φ = 20183530353712.

The previous prime is 21101010111169. The next prime is 21101010111229. The reversal of 21101010111221 is 12211101010112.

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 21101010111221 - 2¹⁰ = 21101010110197 is a prime.

It is a super-2 number, since 2×21101010111221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101010111196 and 21101010111205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101010111229) 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, 15085076 + ... + 16424418.

It is an arithmetic number, because the mean of its divisors is an integer number (2752311739680).

Almost surely, 2^{21101010111221} is an apocalyptic number.

It is an amenable number.

21101010111221 is a deficient number, since it is larger than the sum of its proper divisors (917483806219).

21101010111221 is a wasteful number, since it uses less digits than its factorization.

21101010111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2024355.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21101010111221 its reverse (12211101010112), we get a palindrome (33312111121333).

The spelling of 21101010111221 in words is "twenty-one trillion, one hundred one billion, ten million, one hundred eleven thousand, two hundred twenty-one".