21044435 has 4 divisors (see below), whose sum is σ = 25253328. Its totient is φ = 16835544.

The previous prime is 21044431. The next prime is 21044467. The reversal of 21044435 is 53444012.

21044435 = 823² + 824² + ... + 852².

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 21044435 - 2² = 21044431 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 21044435.

It is not an unprimeable number, because it can be changed into a prime (21044431) 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, 2104439 + ... + 2104448.

It is an arithmetic number, because the mean of its divisors is an integer number (6313332).

Almost surely, 2^21044435 is an apocalyptic number.

21044435 is a deficient number, since it is larger than the sum of its proper divisors (4208893).

21044435 is an equidigital number, since it uses as much as digits as its factorization.

21044435 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4208892.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 21044435 is about 4587.4213889722. The cubic root of 21044435 is about 276.0868722896.

Adding to 21044435 its reverse (53444012), we get a palindrome (74488447).

The spelling of 21044435 in words is "twenty-one million, forty-four thousand, four hundred thirty-five".