21000112221 has 16 divisors (see below), whose sum is σ = 30676726080. Its totient is φ = 12672712320.

The previous prime is 21000112207. The next prime is 21000112247. The reversal of 21000112221 is 12221100012.

It is not a de Polignac number, because 21000112221 - 2¹⁸ = 20999850077 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000112197 and 21000112206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000112321) 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 15 ways as a sum of consecutive naturals, for example, 1357906 + ... + 1373283.

It is an arithmetic number, because the mean of its divisors is an integer number (1917295380).

Almost surely, 2^21000112221 is an apocalyptic number.

It is an amenable number.

21000112221 is a deficient number, since it is larger than the sum of its proper divisors (9676613859).

21000112221 is a wasteful number, since it uses less digits than its factorization.

21000112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2731436.

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

Adding to 21000112221 its reverse (12221100012), we get a palindrome (33221212233).

It can be divided in two parts, 210001 and 12221, that added together give a palindrome (222222).

The spelling of 21000112221 in words is "twenty-one billion, one hundred twelve thousand, two hundred twenty-one".