21100002002221 has 4 divisors (see below), whose sum is σ = 21129025389472. Its totient is φ = 21070978614972.

The previous prime is 21100002002207. The next prime is 21100002002291. The reversal of 21100002002221 is 12220020000112.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-21100002002221 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 (21100002002201) 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 3 ways as a sum of consecutive naturals, for example, 14511692535 + ... + 14511693988.

It is an arithmetic number, because the mean of its divisors is an integer number (5282256347368).

Almost surely, 2^{21100002002221} is an apocalyptic number.

It is an amenable number.

21100002002221 is a deficient number, since it is larger than the sum of its proper divisors (29023387251).

21100002002221 is an equidigital number, since it uses as much as digits as its factorization.

21100002002221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29023387250.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21100002002221 its reverse (12220020000112), we get a palindrome (33320022002333).

The spelling of 21100002002221 in words is "twenty-one trillion, one hundred billion, two million, two thousand, two hundred twenty-one".