21002001201121 has 4 divisors (see below), whose sum is σ = 21002218738992. Its totient is φ = 21001783663252.

The previous prime is 21002001201113. The next prime is 21002001201151. The reversal of 21002001201121 is 12110210020012.

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 21002001201121 - 2³ = 21002001201113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002001201151) 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, 108624055 + ... + 108817228.

It is an arithmetic number, because the mean of its divisors is an integer number (5250554684748).

Almost surely, 2^{21002001201121} is an apocalyptic number.

It is an amenable number.

21002001201121 is a deficient number, since it is larger than the sum of its proper divisors (217537871).

21002001201121 is an equidigital number, since it uses as much as digits as its factorization.

21002001201121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217537870.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21002001201121 its reverse (12110210020012), we get a palindrome (33112211221133).

The spelling of 21002001201121 in words is "twenty-one trillion, two billion, one million, two hundred one thousand, one hundred twenty-one".