21221100110221 has 16 divisors (see below), whose sum is σ = 23189683765248. Its totient is φ = 19259108866800.

The previous prime is 21221100110207. The next prime is 21221100110239. The reversal of 21221100110221 is 12201100112212.

It is not a de Polignac number, because 21221100110221 - 2¹³ = 21221100102029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21221100110195 and 21221100110204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221100110201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15101076 + ... + 16446418.

It is an arithmetic number, because the mean of its divisors is an integer number (1449355235328).

Almost surely, 2^{21221100110221} is an apocalyptic number.

It is an amenable number.

21221100110221 is a deficient number, since it is larger than the sum of its proper divisors (1968583655027).

21221100110221 is a wasteful number, since it uses less digits than its factorization.

21221100110221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1347792.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21221100110221 its reverse (12201100112212), we get a palindrome (33422200222433).

The spelling of 21221100110221 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred million, one hundred ten thousand, two hundred twenty-one".