21345336 has 64 divisors (see below), whose sum is σ = 62791200. Its totient is φ = 6695424.

The previous prime is 21345287. The next prime is 21345347. The reversal of 21345336 is 63354312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

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 in 15 ways as a sum of consecutive naturals, for example, 766 + ... + 6578.

Almost surely, 2^21345336 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21345336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31395600).

21345336 is an abundant number, since it is smaller than the sum of its proper divisors (41445864).

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

21345336 is a wasteful number, since it uses less digits than its factorization.

21345336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5845 (or 5835 counting only the distinct ones).

The product of its digits is 6480, while the sum is 27.

The square root of 21345336 is about 4620.1012975908. The cubic root of 21345336 is about 277.3965136402.

Adding to 21345336 its reverse (63354312), we get a palindrome (84699648).

The spelling of 21345336 in words is "twenty-one million, three hundred forty-five thousand, three hundred thirty-six".