21001304 has 8 divisors (see below), whose sum is σ = 39377460. Its totient is φ = 10500648.

The previous prime is 21001247. The next prime is 21001319. The reversal of 21001304 is 40310012.

It is a happy number.

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

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, 1312574 + ... + 1312589.

Almost surely, 2^21001304 is an apocalyptic number.

It is an amenable number.

21001304 is a deficient number, since it is larger than the sum of its proper divisors (18376156).

21001304 is a wasteful number, since it uses less digits than its factorization.

21001304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2625169 (or 2625165 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21001304 is about 4582.7179708116. The cubic root of 21001304 is about 275.8981280550.

Adding to 21001304 its reverse (40310012), we get a palindrome (61311316).

The spelling of 21001304 in words is "twenty-one million, one thousand, three hundred four".