21210221011121 has 8 divisors (see below), whose sum is σ = 21704155133760. Its totient is φ = 20716317487152.

The previous prime is 21210221011117. The next prime is 21210221011181. The reversal of 21210221011121 is 12111012201212.

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 21210221011121 - 2² = 21210221011117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21210221011121.

It is not an unprimeable number, because it can be changed into a prime (21210221011181) 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 7 ways as a sum of consecutive naturals, for example, 6244205 + ... + 9022778.

It is an arithmetic number, because the mean of its divisors is an integer number (2713019391720).

Almost surely, 2^{21210221011121} is an apocalyptic number.

It is an amenable number.

21210221011121 is a deficient number, since it is larger than the sum of its proper divisors (493934122639).

21210221011121 is a wasteful number, since it uses less digits than its factorization.

21210221011121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15299335.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21210221011121 its reverse (12111012201212), we get a palindrome (33321233212333).

The spelling of 21210221011121 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty-one million, eleven thousand, one hundred twenty-one".