21210100010221 has 4 divisors (see below), whose sum is σ = 21231502735744. Its totient is φ = 21188697284700.

The previous prime is 21210100010219. The next prime is 21210100010237. The reversal of 21210100010221 is 12201000101212.

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 21210100010221 - 2¹ = 21210100010219 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 (21510100010221) 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, 10701361275 + ... + 10701363256.

It is an arithmetic number, because the mean of its divisors is an integer number (5307875683936).

Almost surely, 2^{21210100010221} is an apocalyptic number.

It is an amenable number.

21210100010221 is a deficient number, since it is larger than the sum of its proper divisors (21402725523).

21210100010221 is an equidigital number, since it uses as much as digits as its factorization.

21210100010221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21402725522.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21210100010221 its reverse (12201000101212), we get a palindrome (33411100111433).

Subtracting from 21210100010221 its reverse (12201000101212), we obtain a palindrome (9009099909009).

The spelling of 21210100010221 in words is "twenty-one trillion, two hundred ten billion, one hundred million, ten thousand, two hundred twenty-one".