21321136 has 10 divisors (see below), whose sum is σ = 41309732. Its totient is φ = 10660560.

The previous prime is 21321133. The next prime is 21321169. The reversal of 21321136 is 63112312.

It is not an unprimeable number, because it can be changed into a prime (21321133) 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, 666270 + ... + 666301.

Almost surely, 2^21321136 is an apocalyptic number.

It is an amenable number.

21321136 is a deficient number, since it is larger than the sum of its proper divisors (19988596).

21321136 is a wasteful number, since it uses less digits than its factorization.

21321136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1332579 (or 1332573 counting only the distinct ones).

The product of its digits is 216, while the sum is 19.

The square root of 21321136 is about 4617.4815646627. The cubic root of 21321136 is about 277.2916424222.

Adding to 21321136 its reverse (63112312), we get a palindrome (84433448).

The spelling of 21321136 in words is "twenty-one million, three hundred twenty-one thousand, one hundred thirty-six".