21210121121 has 8 divisors (see below), whose sum is σ = 24241089600. Its totient is φ = 18179390448.

The previous prime is 21210121081. The next prime is 21210121147. The reversal of 21210121121 is 12112101212.

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

It is a cyclic number.

It is not a de Polignac number, because 21210121121 - 2¹⁸ = 21209858977 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21210121096 and 21210121105.

It is not an unprimeable number, because it can be changed into a prime (21210121151) 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, 218030 + ... + 299928.

It is an arithmetic number, because the mean of its divisors is an integer number (3030136200).

Almost surely, 2^21210121121 is an apocalyptic number.

It is an amenable number.

21210121121 is a deficient number, since it is larger than the sum of its proper divisors (3030968479).

21210121121 is an equidigital number, since it uses as much as digits as its factorization.

21210121121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118903.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21210121121 its reverse (12112101212), we get a palindrome (33322222333).

The spelling of 21210121121 in words is "twenty-one billion, two hundred ten million, one hundred twenty-one thousand, one hundred twenty-one".