21636304 has 10 divisors (see below), whose sum is σ = 41920370. Its totient is φ = 10818144.

The previous prime is 21636301. The next prime is 21636317. The reversal of 21636304 is 40363612.

It can be written as a sum of positive squares in only one way, i.e., 21603904 + 32400 = 4648^2 + 180^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21636301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 676119 + ... + 676150.

It is an arithmetic number, because the mean of its divisors is an integer number (4192037).

Almost surely, 2^21636304 is an apocalyptic number.

It is an amenable number.

21636304 is a deficient number, since it is larger than the sum of its proper divisors (20284066).

21636304 is a wasteful number, since it uses less digits than its factorization.

21636304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1352277 (or 1352271 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 21636304 is about 4651.4840642530. The cubic root of 21636304 is about 278.6512688342.

Adding to 21636304 its reverse (40363612), we get a palindrome (61999916).

The spelling of 21636304 in words is "twenty-one million, six hundred thirty-six thousand, three hundred four".