21144111 has 4 divisors (see below), whose sum is σ = 28192152. Its totient is φ = 14096072.

The previous prime is 21144083. The next prime is 21144119. The reversal of 21144111 is 11144112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21144111 - 2¹⁴ = 21127727 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3524016 + ... + 3524021.

It is an arithmetic number, because the mean of its divisors is an integer number (7048038).

Almost surely, 2^21144111 is an apocalyptic number.

21144111 is a deficient number, since it is larger than the sum of its proper divisors (7048041).

21144111 is an equidigital number, since it uses as much as digits as its factorization.

21144111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7048040.

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

The square root of 21144111 is about 4598.2726104484. The cubic root of 21144111 is about 276.5220768332.

Adding to 21144111 its reverse (11144112), we get a palindrome (32288223).

Subtracting from 21144111 its reverse (11144112), we obtain a palindrome (9999999).

The spelling of 21144111 in words is "twenty-one million, one hundred forty-four thousand, one hundred eleven".