21210212002221 has 48 divisors (see below), whose sum is σ = 34711133446080. Its totient is φ = 12366719228160.

The previous prime is 21210212002183. The next prime is 21210212002261. The reversal of 21210212002221 is 12220021201212.

It is a happy number.

21210212002221 is a `hidden beast` number, since 21 + 210 + 212 + 0 + 0 + 2 + 221 = 666.

It is not a de Polignac number, because 21210212002221 - 2⁶ = 21210212002157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21210212002194 and 21210212002203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210212002261) 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 47 ways as a sum of consecutive naturals, for example, 32204295 + ... + 32856308.

It is an arithmetic number, because the mean of its divisors is an integer number (723148613460).

Almost surely, 2^{21210212002221} is an apocalyptic number.

It is an amenable number.

21210212002221 is a deficient number, since it is larger than the sum of its proper divisors (13500921443859).

21210212002221 is a wasteful number, since it uses less digits than its factorization.

21210212002221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65060746 (or 65060743 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21210212002221 its reverse (12220021201212), we get a palindrome (33430233203433).

The spelling of 21210212002221 in words is "twenty-one trillion, two hundred ten billion, two hundred twelve million, two thousand, two hundred twenty-one".