21124443 has 8 divisors (see below), whose sum is σ = 28190800. Its totient is φ = 14070528.

The previous prime is 21124391. The next prime is 21124459. The reversal of 21124443 is 34442112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21124443 - 2¹⁶ = 21058907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21124463) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2103 + ... + 6831.

It is an arithmetic number, because the mean of its divisors is an integer number (3523850).

Almost surely, 2^21124443 is an apocalyptic number.

21124443 is a deficient number, since it is larger than the sum of its proper divisors (7066357).

21124443 is a wasteful number, since it uses less digits than its factorization.

21124443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6221.

The product of its digits is 768, while the sum is 21.

The square root of 21124443 is about 4596.1334837013. The cubic root of 21124443 is about 276.4363110550.

Adding to 21124443 its reverse (34442112), we get a palindrome (55566555).

It can be divided in two parts, 2112 and 4443, that added together give a triangular number (6555 = T₁₁₄).

The spelling of 21124443 in words is "twenty-one million, one hundred twenty-four thousand, four hundred forty-three".