21800445 has 16 divisors (see below), whose sum is σ = 35324160. Its totient is φ = 11479104.

The previous prime is 21800417. The next prime is 21800453. The reversal of 21800445 is 54400812.

It is not a de Polignac number, because 21800445 - 2⁵ = 21800413 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8014 + ... + 10383.

It is an arithmetic number, because the mean of its divisors is an integer number (2207760).

Almost surely, 2^21800445 is an apocalyptic number.

It is an amenable number.

21800445 is a deficient number, since it is larger than the sum of its proper divisors (13523715).

21800445 is a wasteful number, since it uses less digits than its factorization.

21800445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18484.

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 21800445 is about 4669.0946659925. The cubic root of 21800445 is about 279.3541449031.

The spelling of 21800445 in words is "twenty-one million, eight hundred thousand, four hundred forty-five".