21313304 has 8 divisors (see below), whose sum is σ = 39962460. Its totient is φ = 10656648.

The previous prime is 21313301. The next prime is 21313333. The reversal of 21313304 is 40331312.

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 not an unprimeable number, because it can be changed into a prime (21313301) 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, 1332074 + ... + 1332089.

Almost surely, 2^21313304 is an apocalyptic number.

It is an amenable number.

21313304 is a deficient number, since it is larger than the sum of its proper divisors (18649156).

21313304 is a wasteful number, since it uses less digits than its factorization.

21313304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2664169 (or 2664165 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 21313304 is about 4616.6334054157. The cubic root of 21313304 is about 277.2576852866.

Adding to 21313304 its reverse (40331312), we get a palindrome (61644616).

The spelling of 21313304 in words is "twenty-one million, three hundred thirteen thousand, three hundred four".