21113021121 has 8 divisors (see below), whose sum is σ = 28151527584. Its totient is φ = 14074931040.

The previous prime is 21113021029. The next prime is 21113021129. The reversal of 21113021121 is 12112031112.

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

It is not a de Polignac number, because 21113021121 - 2¹⁵ = 21112988353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21113021121.

It is not an unprimeable number, because it can be changed into a prime (21113021129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44541 + ... + 210261.

It is an arithmetic number, because the mean of its divisors is an integer number (3518940948).

Almost surely, 2^21113021121 is an apocalyptic number.

It is an amenable number.

21113021121 is a deficient number, since it is larger than the sum of its proper divisors (7038506463).

21113021121 is a wasteful number, since it uses less digits than its factorization.

21113021121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208191.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21113021121 its reverse (12112031112), we get a palindrome (33225052233).

Subtracting from 21113021121 its reverse (12112031112), we obtain a palindrome (9000990009).

The spelling of 21113021121 in words is "twenty-one billion, one hundred thirteen million, twenty-one thousand, one hundred twenty-one".