21100222120121 has 4 divisors (see below), whose sum is σ = 21101926650000. Its totient is φ = 21098517590244.

The previous prime is 21100222120079. The next prime is 21100222120139. The reversal of 21100222120121 is 12102122200112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21100222120121 - 2⁴² = 16702175609017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21100222120121.

It is not an unprimeable number, because it can be changed into a prime (21100222120151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 852246371 + ... + 852271128.

It is an arithmetic number, because the mean of its divisors is an integer number (5275481662500).

Almost surely, 2^{21100222120121} is an apocalyptic number.

It is an amenable number.

21100222120121 is a deficient number, since it is larger than the sum of its proper divisors (1704529879).

21100222120121 is a wasteful number, since it uses less digits than its factorization.

21100222120121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1704529878.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21100222120121 its reverse (12102122200112), we get a palindrome (33202344320233).

The spelling of 21100222120121 in words is "twenty-one trillion, one hundred billion, two hundred twenty-two million, one hundred twenty thousand, one hundred twenty-one".