21344543 has 16 divisors (see below), whose sum is σ = 24864000. Its totient is φ = 18118080.

The previous prime is 21344513. The next prime is 21344593. The reversal of 21344543 is 34544312.

It is a cyclic number.

It is not a de Polignac number, because 21344543 - 2¹⁰ = 21343519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21344513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14558 + ... + 15956.

It is an arithmetic number, because the mean of its divisors is an integer number (1554000).

Almost surely, 2^21344543 is an apocalyptic number.

21344543 is a deficient number, since it is larger than the sum of its proper divisors (3519457).

21344543 is a wasteful number, since it uses less digits than its factorization.

21344543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1502.

The product of its digits is 5760, while the sum is 26.

The square root of 21344543 is about 4620.0154761646. The cubic root of 21344543 is about 277.3930784142.

Adding to 21344543 its reverse (34544312), we get a palindrome (55888855).

The spelling of 21344543 in words is "twenty-one million, three hundred forty-four thousand, five hundred forty-three".