21321364 has 12 divisors (see below), whose sum is σ = 37474164. Its totient is φ = 10614464.

The previous prime is 21321359. The next prime is 21321367. The reversal of 21321364 is 46312312.

It can be written as a sum of positive squares in 2 ways, for example, as 11957764 + 9363600 = 3458^2 + 3060^2 .

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321367) 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 3 ways as a sum of consecutive naturals, for example, 10507 + ... + 12370.

It is an arithmetic number, because the mean of its divisors is an integer number (3122847).

Almost surely, 2^21321364 is an apocalyptic number.

It is an amenable number.

21321364 is a deficient number, since it is larger than the sum of its proper divisors (16152800).

21321364 is a wasteful number, since it uses less digits than its factorization.

21321364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23114 (or 23112 counting only the distinct ones).

The product of its digits is 864, while the sum is 22.

The square root of 21321364 is about 4617.5062533796. The cubic root of 21321364 is about 277.2926308353.

Adding to 21321364 its reverse (46312312), we get a palindrome (67633676).

The spelling of 21321364 in words is "twenty-one million, three hundred twenty-one thousand, three hundred sixty-four".