21200044 has 24 divisors (see below), whose sum is σ = 38631600. Its totient is φ = 10167360.

The previous prime is 21200041. The next prime is 21200051. The reversal of 21200044 is 44000212.

It is a junction number, because it is equal to n+sod(n) for n = 21199997 and 21200033.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20254 + ... + 21274.

It is an arithmetic number, because the mean of its divisors is an integer number (1609650).

Almost surely, 2^21200044 is an apocalyptic number.

It is an amenable number.

21200044 is a deficient number, since it is larger than the sum of its proper divisors (17431556).

21200044 is a wasteful number, since it uses less digits than its factorization.

21200044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1233 (or 1231 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 21200044 is about 4604.3505513807. The cubic root of 21200044 is about 276.7656922017.

Adding to 21200044 its reverse (44000212), we get a palindrome (65200256).

The spelling of 21200044 in words is "twenty-one million, two hundred thousand, forty-four".