21321336 has 16 divisors (see below), whose sum is σ = 53303400. Its totient is φ = 7107104.

The previous prime is 21321331. The next prime is 21321337. The reversal of 21321336 is 63312312.

It is a nude number because it is divisible by every one of its digits.

It is a plaindrome in base 13 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 444171 + ... + 444218.

Almost surely, 2^21321336 is an apocalyptic number.

It is an amenable number.

21321336 is an abundant number, since it is smaller than the sum of its proper divisors (31982064).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21321336 is a wasteful number, since it uses less digits than its factorization.

21321336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 888398 (or 888394 counting only the distinct ones).

The product of its digits is 648, while the sum is 21.

The square root of 21321336 is about 4617.5032214390. The cubic root of 21321336 is about 277.2925094516.

Adding to 21321336 its reverse (63312312), we get a palindrome (84633648).

The spelling of 21321336 in words is "twenty-one million, three hundred twenty-one thousand, three hundred thirty-six".