21100000101221 has 32 divisors (see below), whose sum is σ = 21893801402880. Its totient is φ = 20323619656704.

The previous prime is 21100000101217. The next prime is 21100000101263. The reversal of 21100000101221 is 12210100000112.

It is a cyclic number.

It is not a de Polignac number, because 21100000101221 - 2² = 21100000101217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100000101121) 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 31 ways as a sum of consecutive naturals, for example, 1311610040 + ... + 1311626126.

It is an arithmetic number, because the mean of its divisors is an integer number (684181293840).

Almost surely, 2^{21100000101221} is an apocalyptic number.

It is an amenable number.

21100000101221 is a deficient number, since it is larger than the sum of its proper divisors (793801301659).

21100000101221 is a wasteful number, since it uses less digits than its factorization.

21100000101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17765.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21100000101221 its reverse (12210100000112), we get a palindrome (33310100101333).

The spelling of 21100000101221 in words is "twenty-one trillion, one hundred billion, one hundred one thousand, two hundred twenty-one".