21315332 has 6 divisors (see below), whose sum is σ = 37301838. Its totient is φ = 10657664.

The previous prime is 21315289. The next prime is 21315341. The reversal of 21315332 is 23351312.

It can be written as a sum of positive squares in only one way, i.e., 14638276 + 6677056 = 3826^2 + 2584^2 .

It is an unprimeable number.

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, 2664413 + ... + 2664420.

It is an arithmetic number, because the mean of its divisors is an integer number (6216973).

Almost surely, 2^21315332 is an apocalyptic number.

It is an amenable number.

21315332 is a deficient number, since it is larger than the sum of its proper divisors (15986506).

21315332 is a wasteful number, since it uses less digits than its factorization.

21315332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5328837 (or 5328835 counting only the distinct ones).

The product of its digits is 540, while the sum is 20.

The square root of 21315332 is about 4616.8530407627. The cubic root of 21315332 is about 277.2664788670.

Adding to 21315332 its reverse (23351312), we get a palindrome (44666644).

The spelling of 21315332 in words is "twenty-one million, three hundred fifteen thousand, three hundred thirty-two".