21210122210221 has 16 divisors (see below), whose sum is σ = 24547176710784. Its totient is φ = 17950094599104.

The previous prime is 21210122210171. The next prime is 21210122210281. The reversal of 21210122210221 is 12201222101212.

It is a cyclic number.

It is not a de Polignac number, because 21210122210221 - 2⁷ = 21210122210093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210122210281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10199250 + ... + 12101443.

It is an arithmetic number, because the mean of its divisors is an integer number (1534198544424).

Almost surely, 2^{21210122210221} is an apocalyptic number.

It is an amenable number.

21210122210221 is a deficient number, since it is larger than the sum of its proper divisors (3337054500563).

21210122210221 is a wasteful number, since it uses less digits than its factorization.

21210122210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22302420.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21210122210221 its reverse (12201222101212), we get a palindrome (33411344311433).

The spelling of 21210122210221 in words is "twenty-one trillion, two hundred ten billion, one hundred twenty-two million, two hundred ten thousand, two hundred twenty-one".