21110001121 has 4 divisors (see below), whose sum is σ = 23029092144. Its totient is φ = 19190910100.

The previous prime is 21110001103. The next prime is 21110001131. The reversal of 21110001121 is 12110001112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21110001121 - 2¹⁹ = 21109476833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21110001098 and 21110001107.

It is not an unprimeable number, because it can be changed into a prime (21110001131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 959545495 + ... + 959545516.

It is an arithmetic number, because the mean of its divisors is an integer number (5757273036).

Almost surely, 2^21110001121 is an apocalyptic number.

It is an amenable number.

21110001121 is a deficient number, since it is larger than the sum of its proper divisors (1919091023).

21110001121 is a wasteful number, since it uses less digits than its factorization.

21110001121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1919091022.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21110001121 its reverse (12110001112), we get a palindrome (33220002233).

Subtracting from 21110001121 its reverse (12110001112), we obtain a palindrome (9000000009).

The spelling of 21110001121 in words is "twenty-one billion, one hundred ten million, one thousand, one hundred twenty-one".