21336636 has 48 divisors (see below), whose sum is σ = 51287040. Its totient is φ = 6901440.

The previous prime is 21336613. The next prime is 21336647. The reversal of 21336636 is 63663312.

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

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, 67150 + ... + 67466.

It is an arithmetic number, because the mean of its divisors is an integer number (1068480).

Almost surely, 2^21336636 is an apocalyptic number.

It is an amenable number.

21336636 is an abundant number, since it is smaller than the sum of its proper divisors (29950404).

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

21336636 is a wasteful number, since it uses less digits than its factorization.

21336636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474 (or 472 counting only the distinct ones).

The product of its digits is 11664, while the sum is 30.

The square root of 21336636 is about 4619.1596638350. The cubic root of 21336636 is about 277.3588211341.

Adding to 21336636 its reverse (63663312), we get a palindrome (84999948).

The spelling of 21336636 in words is "twenty-one million, three hundred thirty-six thousand, six hundred thirty-six".