21100010220221 has 4 divisors (see below), whose sum is σ = 21100155951744. Its totient is φ = 21099864488700.

The previous prime is 21100010220197. The next prime is 21100010220227. The reversal of 21100010220221 is 12202201000112.

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-21100010220221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21100010220196 and 21100010220205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100010220227) 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, 72648365 + ... + 72938226.

It is an arithmetic number, because the mean of its divisors is an integer number (5275038987936).

Almost surely, 2^{21100010220221} is an apocalyptic number.

It is an amenable number.

21100010220221 is a deficient number, since it is larger than the sum of its proper divisors (145731523).

21100010220221 is a wasteful number, since it uses less digits than its factorization.

21100010220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145731522.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21100010220221 its reverse (12202201000112), we get a palindrome (33302211220333).

The spelling of 21100010220221 in words is "twenty-one trillion, one hundred billion, ten million, two hundred twenty thousand, two hundred twenty-one".