21203221121 has 8 divisors (see below), whose sum is σ = 21248004000. Its totient is φ = 21158465760.

The previous prime is 21203221103. The next prime is 21203221159. The reversal of 21203221121 is 12112230212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21203221121 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 21203221121.

It is not an unprimeable number, because it can be changed into a prime (21203221421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2327786 + ... + 2336876.

It is an arithmetic number, because the mean of its divisors is an integer number (2656000500).

Almost surely, 2^21203221121 is an apocalyptic number.

It is an amenable number.

21203221121 is a deficient number, since it is larger than the sum of its proper divisors (44782879).

21203221121 is an equidigital number, since it uses as much as digits as its factorization.

21203221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13759.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21203221121 its reverse (12112230212), we get a palindrome (33315451333).

Subtracting from 21203221121 its reverse (12112230212), we obtain a palindrome (9090990909).

The spelling of 21203221121 in words is "twenty-one billion, two hundred three million, two hundred twenty-one thousand, one hundred twenty-one".