21472543 has 4 divisors (see below), whose sum is σ = 22052920. Its totient is φ = 20892168.

The previous prime is 21472541. The next prime is 21472559. The reversal of 21472543 is 34527412.

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 21472543 - 2¹ = 21472541 is a prime.

It is a super-2 number, since 2×21472543² = 922140205773698, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21472541) 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, 290133 + ... + 290206.

It is an arithmetic number, because the mean of its divisors is an integer number (5513230).

Almost surely, 2^21472543 is an apocalyptic number.

21472543 is a deficient number, since it is larger than the sum of its proper divisors (580377).

21472543 is an equidigital number, since it uses as much as digits as its factorization.

21472543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580376.

The product of its digits is 6720, while the sum is 28.

The square root of 21472543 is about 4633.8475374142. The cubic root of 21472543 is about 277.9464684809.

Adding to 21472543 its reverse (34527412), we get a palindrome (55999955).

The spelling of 21472543 in words is "twenty-one million, four hundred seventy-two thousand, five hundred forty-three".