21000111222 has 16 divisors (see below), whose sum is σ = 43826319360. Its totient is φ = 6695687592.

The previous prime is 21000111179. The next prime is 21000111227. The reversal of 21000111222 is 22211100012.

It is a junction number, because it is equal to n+sod(n) for n = 21000111198 and 21000111207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000111227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76087222 + ... + 76087497.

It is an arithmetic number, because the mean of its divisors is an integer number (2739144960).

Almost surely, 2^21000111222 is an apocalyptic number.

21000111222 is an abundant number, since it is smaller than the sum of its proper divisors (22826208138).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21000111222 is a wasteful number, since it uses less digits than its factorization.

21000111222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152174747.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21000111222 its reverse (22211100012), we get a palindrome (43211211234).

The spelling of 21000111222 in words is "twenty-one billion, one hundred eleven thousand, two hundred twenty-two".