21304367 has 6 divisors (see below), whose sum is σ = 24782688. Its totient is φ = 18260844.

The previous prime is 21304351. The next prime is 21304373. The reversal of 21304367 is 76340312.

It is not a de Polignac number, because 21304367 - 2⁴ = 21304351 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21304397) 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 in 5 ways as a sum of consecutive naturals, for example, 217343 + ... + 217440.

It is an arithmetic number, because the mean of its divisors is an integer number (4130448).

Almost surely, 2^21304367 is an apocalyptic number.

21304367 is a deficient number, since it is larger than the sum of its proper divisors (3478321).

21304367 is an equidigital number, since it uses as much as digits as its factorization.

21304367 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434797 (or 434790 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 26.

The square root of 21304367 is about 4615.6653908185. The cubic root of 21304367 is about 277.2189270483.

Adding to 21304367 its reverse (76340312), we get a palindrome (97644679).

The spelling of 21304367 in words is "twenty-one million, three hundred four thousand, three hundred sixty-seven".