21100210202221 has 8 divisors (see below), whose sum is σ = 21847240738080. Its totient is φ = 20354475471792.

The previous prime is 21100210202173. The next prime is 21100210202237. The reversal of 21100210202221 is 12220201200112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21100210202221 - 2²¹ = 21100208105069 is a prime.

It is a super-2 number, since 2×21100210202221² (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 = 21100210202195 and 21100210202204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100210202321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323918215 + ... + 323983348.

It is an arithmetic number, because the mean of its divisors is an integer number (2730905092260).

Almost surely, 2^{21100210202221} is an apocalyptic number.

It is an amenable number.

21100210202221 is a deficient number, since it is larger than the sum of its proper divisors (747030535859).

21100210202221 is a wasteful number, since it uses less digits than its factorization.

21100210202221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647902715.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21100210202221 its reverse (12220201200112), we get a palindrome (33320411402333).

The spelling of 21100210202221 in words is "twenty-one trillion, one hundred billion, two hundred ten million, two hundred two thousand, two hundred twenty-one".