21033543 has 4 divisors (see below), whose sum is σ = 28044728. Its totient is φ = 14022360.

The previous prime is 21033541. The next prime is 21033557. The reversal of 21033543 is 34533012.

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

It is not a de Polignac number, because 21033543 - 2¹ = 21033541 is a prime.

It is a super-2 number, since 2×21033543² = 884819862265698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033541) 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, 3505588 + ... + 3505593.

It is an arithmetic number, because the mean of its divisors is an integer number (7011182).

Almost surely, 2^21033543 is an apocalyptic number.

21033543 is a deficient number, since it is larger than the sum of its proper divisors (7011185).

21033543 is an equidigital number, since it uses as much as digits as its factorization.

21033543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7011184.

The product of its (nonzero) digits is 1080, while the sum is 21.

The square root of 21033543 is about 4586.2340760149. The cubic root of 21033543 is about 276.0392325032.

Adding to 21033543 its reverse (34533012), we get a palindrome (55566555).

The spelling of 21033543 in words is "twenty-one million, thirty-three thousand, five hundred forty-three".