21130543 has 4 divisors (see below), whose sum is σ = 24149200. Its totient is φ = 18111888.

The previous prime is 21130511. The next prime is 21130573. The reversal of 21130543 is 34503112.

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 21130543 - 2⁵ = 21130511 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21130543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130573) 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 3 ways as a sum of consecutive naturals, for example, 1509318 + ... + 1509331.

It is an arithmetic number, because the mean of its divisors is an integer number (6037300).

Almost surely, 2^21130543 is an apocalyptic number.

21130543 is a deficient number, since it is larger than the sum of its proper divisors (3018657).

21130543 is an equidigital number, since it uses as much as digits as its factorization.

21130543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3018656.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21130543 is about 4596.7970370683. The cubic root of 21130543 is about 276.4629168723.

Adding to 21130543 its reverse (34503112), we get a palindrome (55633655).

The spelling of 21130543 in words is "twenty-one million, one hundred thirty thousand, five hundred forty-three".