21836136 has 64 divisors (see below), whose sum is σ = 63475200. Its totient is φ = 6130368.

The previous prime is 21836123. The next prime is 21836147. The reversal of 21836136 is 63163812.

21836136 is a nontrivial binomial coefficient, being equal to C(6609, 2).

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

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, 8811 + ... + 11013.

It is an arithmetic number, because the mean of its divisors is an integer number (991800).

Almost surely, 2^21836136 is an apocalyptic number.

21836136 is the 6608-th triangular number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21836136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31737600).

21836136 is an abundant number, since it is smaller than the sum of its proper divisors (41639064).

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

21836136 is a wasteful number, since it uses less digits than its factorization.

21836136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2278 (or 2274 counting only the distinct ones).

The product of its digits is 5184, while the sum is 30.

The square root of 21836136 is about 4672.9151500964. The cubic root of 21836136 is about 279.5065117109.

Adding to 21836136 its reverse (63163812), we get a palindrome (84999948).

The spelling of 21836136 in words is "twenty-one million, eight hundred thirty-six thousand, one hundred thirty-six".