21112000111221 has 16 divisors (see below), whose sum is σ = 28942308181248. Its totient is φ = 13680712857600.

The previous prime is 21112000111217. The next prime is 21112000111247. The reversal of 21112000111221 is 12211100021112.

It is a happy number.

It is not a de Polignac number, because 21112000111221 - 2² = 21112000111217 is a prime.

It is a super-2 number, since 2×21112000111221² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21112000111221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112000111201) 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, 316649836 + ... + 316716501.

It is an arithmetic number, because the mean of its divisors is an integer number (1808894261328).

Almost surely, 2^{21112000111221} is an apocalyptic number.

It is an amenable number.

21112000111221 is a deficient number, since it is larger than the sum of its proper divisors (7830308070027).

21112000111221 is a wasteful number, since it uses less digits than its factorization.

21112000111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633366652.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21112000111221 its reverse (12211100021112), we get a palindrome (33323100132333).

The spelling of 21112000111221 in words is "twenty-one trillion, one hundred twelve billion, one hundred eleven thousand, two hundred twenty-one".