21236316 has 24 divisors (see below), whose sum is σ = 49993104. Its totient is φ = 7015680.

The previous prime is 21236311. The next prime is 21236317. The reversal of 21236316 is 61363212.

It is a happy number.

It is a super-2 number, since 2×21236316² = 901962234503712, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21236311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6475 + ... + 9186.

It is an arithmetic number, because the mean of its divisors is an integer number (2083046).

Almost surely, 2^21236316 is an apocalyptic number.

It is an amenable number.

21236316 is an abundant number, since it is smaller than the sum of its proper divisors (28756788).

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

21236316 is a wasteful number, since it uses less digits than its factorization.

21236316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15781 (or 15779 counting only the distinct ones).

The product of its digits is 1296, while the sum is 24.

The square root of 21236316 is about 4608.2877514322. The cubic root of 21236316 is about 276.9234454174.

Adding to 21236316 its reverse (61363212), we get a palindrome (82599528).

The spelling of 21236316 in words is "twenty-one million, two hundred thirty-six thousand, three hundred sixteen".