21101000221221 has 64 divisors (see below), whose sum is σ = 31158676684800. Its totient is φ = 12657161088000.

The previous prime is 21101000221219. The next prime is 21101000221321. The reversal of 21101000221221 is 12212200010112.

It is not a de Polignac number, because 21101000221221 - 2¹ = 21101000221219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21101000221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101000221121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23322505 + ... + 24210353.

It is an arithmetic number, because the mean of its divisors is an integer number (486854323200).

Almost surely, 2^{21101000221221} is an apocalyptic number.

It is an amenable number.

21101000221221 is a deficient number, since it is larger than the sum of its proper divisors (10057676463579).

21101000221221 is a wasteful number, since it uses less digits than its factorization.

21101000221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 888218.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21101000221221 its reverse (12212200010112), we get a palindrome (33313200231333).

The spelling of 21101000221221 in words is "twenty-one trillion, one hundred one billion, two hundred twenty-one thousand, two hundred twenty-one".