210221122120021 has 32 divisors (see below), whose sum is σ = 221785705709568. Its totient is φ = 198861699801600.

The previous prime is 210221122119989. The next prime is 210221122120033. The reversal of 210221122120021 is 120021221122012.

It is a cyclic number.

It is not a de Polignac number, because 210221122120021 - 2⁵ = 210221122119989 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 (210221122120081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22972470796 + ... + 22972479946.

It is an arithmetic number, because the mean of its divisors is an integer number (6930803303424).

Almost surely, 2^{210221122120021} is an apocalyptic number.

It is an amenable number.

210221122120021 is a deficient number, since it is larger than the sum of its proper divisors (11564583589547).

210221122120021 is a wasteful number, since it uses less digits than its factorization.

210221122120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15721.

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

Adding to 210221122120021 its reverse (120021221122012), we get a palindrome (330242343242033).

The spelling of 210221122120021 in words is "two hundred ten trillion, two hundred twenty-one billion, one hundred twenty-two million, one hundred twenty thousand, twenty-one".