21201221012201 has 4 divisors (see below), whose sum is σ = 21207555410832. Its totient is φ = 21194886613572.

The previous prime is 21201221012071. The next prime is 21201221012233. The reversal of 21201221012201 is 10221012210212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21201221012201 - 2³⁸ = 20926343105257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21201221012201.

It is not an unprimeable number, because it can be changed into a prime (21201221012281) 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 3 ways as a sum of consecutive naturals, for example, 3167194295 + ... + 3167200988.

It is an arithmetic number, because the mean of its divisors is an integer number (5301888852708).

Almost surely, 2^{21201221012201} is an apocalyptic number.

It is an amenable number.

21201221012201 is a deficient number, since it is larger than the sum of its proper divisors (6334398631).

21201221012201 is an equidigital number, since it uses as much as digits as its factorization.

21201221012201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6334398630.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21201221012201 its reverse (10221012210212), we get a palindrome (31422233222413).

The spelling of 21201221012201 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-one million, twelve thousand, two hundred one".