21144163 has 4 divisors (see below), whose sum is σ = 21341880. Its totient is φ = 20946448.

The previous prime is 21144121. The next prime is 21144173. The reversal of 21144163 is 36144112.

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 21144163 - 2⁹ = 21143651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21144173) 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, 98698 + ... + 98911.

It is an arithmetic number, because the mean of its divisors is an integer number (5335470).

Almost surely, 2^21144163 is an apocalyptic number.

21144163 is a deficient number, since it is larger than the sum of its proper divisors (197717).

21144163 is a wasteful number, since it uses less digits than its factorization.

21144163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197716.

The product of its digits is 576, while the sum is 22.

The square root of 21144163 is about 4598.2782647421. The cubic root of 21144163 is about 276.5223035178.

Adding to 21144163 its reverse (36144112), we get a palindrome (57288275).

The spelling of 21144163 in words is "twenty-one million, one hundred forty-four thousand, one hundred sixty-three".