21986336 has 12 divisors (see below), whose sum is σ = 43285662. Its totient is φ = 10993152.

The previous prime is 21986333. The next prime is 21986351. The reversal of 21986336 is 63368912.

It can be written as a sum of positive squares in only one way, i.e., 17808400 + 4177936 = 4220^2 + 2044^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21986336.

It is not an unprimeable number, because it can be changed into a prime (21986333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343505 + ... + 343568.

Almost surely, 2^21986336 is an apocalyptic number.

It is an amenable number.

21986336 is a deficient number, since it is larger than the sum of its proper divisors (21299326).

21986336 is an equidigital number, since it uses as much as digits as its factorization.

21986336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 687083 (or 687075 counting only the distinct ones).

The product of its digits is 46656, while the sum is 38.

The square root of 21986336 is about 4688.9589462907. The cubic root of 21986336 is about 280.1459103462.

It can be divided in two parts, 21986 and 336, that added together give a palindrome (22322).

The spelling of 21986336 in words is "twenty-one million, nine hundred eighty-six thousand, three hundred thirty-six".