21201200120221 has 16 divisors (see below), whose sum is σ = 23521133430720. Its totient is φ = 18946707102720.

The previous prime is 21201200120123. The next prime is 21201200120281. The reversal of 21201200120221 is 12202100210212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21201200120221 - 2¹⁷ = 21201199989149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21201200120195 and 21201200120204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201200120281) 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, 29678191 + ... + 30384163.

It is an arithmetic number, because the mean of its divisors is an integer number (1470070839420).

Almost surely, 2^{21201200120221} is an apocalyptic number.

It is an amenable number.

21201200120221 is a deficient number, since it is larger than the sum of its proper divisors (2319933310499).

21201200120221 is a wasteful number, since it uses less digits than its factorization.

21201200120221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752316.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21201200120221 its reverse (12202100210212), we get a palindrome (33403300330433).

The spelling of 21201200120221 in words is "twenty-one trillion, two hundred one billion, two hundred million, one hundred twenty thousand, two hundred twenty-one".