21303404 has 24 divisors (see below), whose sum is σ = 38394048. Its totient is φ = 10337040.

The previous prime is 21303349. The next prime is 21303407. The reversal of 21303404 is 40430312.

It is not an unprimeable number, because it can be changed into a prime (21303407) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35999 + ... + 36585.

It is an arithmetic number, because the mean of its divisors is an integer number (1599752).

Almost surely, 2^21303404 is an apocalyptic number.

It is an amenable number.

21303404 is a deficient number, since it is larger than the sum of its proper divisors (17090644).

21303404 is a wasteful number, since it uses less digits than its factorization.

21303404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845 (or 843 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 21303404 is about 4615.5610709858. The cubic root of 21303404 is about 277.2147500354.

Adding to 21303404 its reverse (40430312), we get a palindrome (61733716).

The spelling of 21303404 in words is "twenty-one million, three hundred three thousand, four hundred four".