21144113 has 4 divisors (see below), whose sum is σ = 21411840. Its totient is φ = 20876388.

The previous prime is 21144083. The next prime is 21144119. The reversal of 21144113 is 31144112.

It is a happy number.

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 21144113 - 2⁶ = 21144049 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21144091 and 21144100.

It is not an unprimeable number, because it can be changed into a prime (21144119) 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, 133745 + ... + 133902.

It is an arithmetic number, because the mean of its divisors is an integer number (5352960).

Almost surely, 2^21144113 is an apocalyptic number.

It is an amenable number.

21144113 is a deficient number, since it is larger than the sum of its proper divisors (267727).

21144113 is an equidigital number, since it uses as much as digits as its factorization.

21144113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267726.

The product of its digits is 96, while the sum is 17.

The square root of 21144113 is about 4598.2728279214. The cubic root of 21144113 is about 276.5220855518.

Adding to 21144113 its reverse (31144112), we get a palindrome (52288225).

Subtracting 21144113 from its reverse (31144112), we obtain a palindrome (9999999).

The spelling of 21144113 in words is "twenty-one million, one hundred forty-four thousand, one hundred thirteen".