21210210222221 has 8 divisors (see below), whose sum is σ = 21720027542400. Its totient is φ = 20706426243360.

The previous prime is 21210210222217. The next prime is 21210210222293. The reversal of 21210210222221 is 12222201201212.

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 21210210222221 - 2² = 21210210222217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210210222193 and 21210210222202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210210222211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1508328215 + ... + 1508342276.

It is an arithmetic number, because the mean of its divisors is an integer number (2715003442800).

Almost surely, 2^{21210210222221} is an apocalyptic number.

It is an amenable number.

21210210222221 is a deficient number, since it is larger than the sum of its proper divisors (509817320179).

21210210222221 is an equidigital number, since it uses as much as digits as its factorization.

21210210222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3016670659.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21210210222221 its reverse (12222201201212), we get a palindrome (33432411423433).

The spelling of 21210210222221 in words is "twenty-one trillion, two hundred ten billion, two hundred ten million, two hundred twenty-two thousand, two hundred twenty-one".