21130444 has 12 divisors (see below), whose sum is σ = 38253600. Its totient is φ = 10200848.

The previous prime is 21130423. The next prime is 21130453. The reversal of 21130444 is 44403112.

It is an unprimeable number.

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, 90964 + ... + 91195.

It is an arithmetic number, because the mean of its divisors is an integer number (3187800).

Almost surely, 2^21130444 is an apocalyptic number.

It is an amenable number.

21130444 is a deficient number, since it is larger than the sum of its proper divisors (17123156).

21130444 is a wasteful number, since it uses less digits than its factorization.

21130444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182192 (or 182190 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21130444 is about 4596.7862686882. The cubic root of 21130444 is about 276.4624851139.

Adding to 21130444 its reverse (44403112), we get a palindrome (65533556).

The spelling of 21130444 in words is "twenty-one million, one hundred thirty thousand, four hundred forty-four".