21030584 has 8 divisors (see below), whose sum is σ = 39432360. Its totient is φ = 10515288.

The previous prime is 21030557. The next prime is 21030589. The reversal of 21030584 is 48503012.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030589) by changing a digit.

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 as a sum of consecutive naturals, namely, 1314404 + ... + 1314419.

It is an arithmetic number, because the mean of its divisors is an integer number (4929045).

Almost surely, 2^21030584 is an apocalyptic number.

It is an amenable number.

21030584 is a deficient number, since it is larger than the sum of its proper divisors (18401776).

21030584 is a wasteful number, since it uses less digits than its factorization.

21030584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2628829 (or 2628825 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21030584 is about 4585.9114688358. The cubic root of 21030584 is about 276.0262874913.

Adding to 21030584 its reverse (48503012), we get a palindrome (69533596).

The spelling of 21030584 in words is "twenty-one million, thirty thousand, five hundred eighty-four".