21001101102221 has 4 divisors (see below), whose sum is σ = 21001139799744. Its totient is φ = 21001062404700.

The previous prime is 21001101102203. The next prime is 21001101102259. The reversal of 21001101102221 is 12220110110012.

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-21001101102221 is a prime.

It is a super-2 number, since 2×21001101102221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001101102196 and 21001101102205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001101102281) 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, 18522965 + ... + 19624026.

It is an arithmetic number, because the mean of its divisors is an integer number (5250284949936).

Almost surely, 2^{21001101102221} is an apocalyptic number.

It is an amenable number.

21001101102221 is a deficient number, since it is larger than the sum of its proper divisors (38697523).

21001101102221 is an equidigital number, since it uses as much as digits as its factorization.

21001101102221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38697522.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21001101102221 its reverse (12220110110012), we get a palindrome (33221211212233).

The spelling of 21001101102221 in words is "twenty-one trillion, one billion, one hundred one million, one hundred two thousand, two hundred twenty-one".