21044535 has 16 divisors (see below), whose sum is σ = 33939456. Its totient is φ = 11134368.

The previous prime is 21044531. The next prime is 21044557. The reversal of 21044535 is 53544012.

It is not a de Polignac number, because 21044535 - 2² = 21044531 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21044531) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3619 + ... + 7428.

It is an arithmetic number, because the mean of its divisors is an integer number (2121216).

Almost surely, 2^21044535 is an apocalyptic number.

21044535 is a deficient number, since it is larger than the sum of its proper divisors (12894921).

21044535 is a wasteful number, since it uses less digits than its factorization.

21044535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11182.

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 21044535 is about 4587.4322883286. The cubic root of 21044535 is about 276.0873095967.

Adding to 21044535 its reverse (53544012), we get a palindrome (74588547).

The spelling of 21044535 in words is "twenty-one million, forty-four thousand, five hundred thirty-five".