21100421121 has 8 divisors (see below), whose sum is σ = 30298040640. Its totient is φ = 12984874512.

The previous prime is 21100421093. The next prime is 21100421171. The reversal of 21100421121 is 12112400112.

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

It is not a de Polignac number, because 21100421121 - 2¹¹ = 21100419073 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21100421121.

It is not an unprimeable number, because it can be changed into a prime (21100421171) 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, 270518181 + ... + 270518258.

It is an arithmetic number, because the mean of its divisors is an integer number (3787255080).

Almost surely, 2^21100421121 is an apocalyptic number.

It is an amenable number.

21100421121 is a deficient number, since it is larger than the sum of its proper divisors (9197619519).

21100421121 is a wasteful number, since it uses less digits than its factorization.

21100421121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541036455.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21100421121 its reverse (12112400112), we get a palindrome (33212821233).

The spelling of 21100421121 in words is "twenty-one billion, one hundred million, four hundred twenty-one thousand, one hundred twenty-one".