21044806 has 4 divisors (see below), whose sum is σ = 31567212. Its totient is φ = 10522402.

The previous prime is 21044797. The next prime is 21044813. The reversal of 21044806 is 60844012.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5261200 + ... + 5261203.

It is an arithmetic number, because the mean of its divisors is an integer number (7891803).

Almost surely, 2^21044806 is an apocalyptic number.

21044806 is a deficient number, since it is larger than the sum of its proper divisors (10522406).

21044806 is a wasteful number, since it uses less digits than its factorization.

21044806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10522405.

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 21044806 is about 4587.4618254542. The cubic root of 21044806 is about 276.0884946920.

Adding to 21044806 its reverse (60844012), we get a palindrome (81888818).

The spelling of 21044806 in words is "twenty-one million, forty-four thousand, eight hundred six".