21200001202121 has 4 divisors (see below), whose sum is σ = 24228572802432. Its totient is φ = 18171429601812.

The previous prime is 21200001202109. The next prime is 21200001202129. The reversal of 21200001202121 is 12120210000212.

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 21200001202121 - 2²² = 21199997007817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21200001202096 and 21200001202105.

It is not an unprimeable number, because it can be changed into a prime (21200001202129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1514285800145 + ... + 1514285800158.

It is an arithmetic number, because the mean of its divisors is an integer number (6057143200608).

Almost surely, 2^{21200001202121} is an apocalyptic number.

It is an amenable number.

21200001202121 is a deficient number, since it is larger than the sum of its proper divisors (3028571600311).

21200001202121 is an equidigital number, since it uses as much as digits as its factorization.

21200001202121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3028571600310.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21200001202121 its reverse (12120210000212), we get a palindrome (33320211202333).

The spelling of 21200001202121 in words is "twenty-one trillion, two hundred billion, one million, two hundred two thousand, one hundred twenty-one".