21201222120201 has 12 divisors (see below), whose sum is σ = 32425398537012. Its totient is φ = 13302727604736.

The previous prime is 21201222120161. The next prime is 21201222120233. The reversal of 21201222120201 is 10202122210212.

It is a happy number.

21201222120201 is a `hidden beast` number, since 2 + 120 + 1 + 222 + 120 + 201 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 19194466560201 + 2006755560000 = 4381149^2 + 1416600^2 .

It is not a de Polignac number, because 21201222120201 - 2³⁰ = 21200148378377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21201292120201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69285039456 + ... + 69285039761.

It is an arithmetic number, because the mean of its divisors is an integer number (2702116544751).

Almost surely, 2^{21201222120201} is an apocalyptic number.

It is an amenable number.

21201222120201 is a deficient number, since it is larger than the sum of its proper divisors (11224176416811).

21201222120201 is a wasteful number, since it uses less digits than its factorization.

21201222120201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138570079240 (or 138570079237 counting only the distinct ones).

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

Adding to 21201222120201 its reverse (10202122210212), we get a palindrome (31403344330413).

The spelling of 21201222120201 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-two million, one hundred twenty thousand, two hundred one".