21225043 has 4 divisors (see below), whose sum is σ = 24257200. Its totient is φ = 18192888.

The previous prime is 21225041. The next prime is 21225047. The reversal of 21225043 is 34052212.

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

It is not a de Polignac number, because 21225043 - 2¹ = 21225041 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 21225043.

It is not an unprimeable number, because it can be changed into a prime (21225041) 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, 1516068 + ... + 1516081.

It is an arithmetic number, because the mean of its divisors is an integer number (6064300).

Almost surely, 2^21225043 is an apocalyptic number.

21225043 is a deficient number, since it is larger than the sum of its proper divisors (3032157).

21225043 is an equidigital number, since it uses as much as digits as its factorization.

21225043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3032156.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21225043 is about 4607.0644666642. The cubic root of 21225043 is about 276.8744364376.

Adding to 21225043 its reverse (34052212), we get a palindrome (55277255).

The spelling of 21225043 in words is "twenty-one million, two hundred twenty-five thousand, forty-three".