21636341 has 2 divisors, whose sum is σ = 21636342. Its totient is φ = 21636340.

The previous prime is 21636331. The next prime is 21636347. The reversal of 21636341 is 14363612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20666116 + 970225 = 4546^2 + 985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21636341 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 21636341.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21636347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10818170 + 10818171.

It is an arithmetic number, because the mean of its divisors is an integer number (10818171).

Almost surely, 2^21636341 is an apocalyptic number.

It is an amenable number.

21636341 is a deficient number, since it is larger than the sum of its proper divisors (1).

21636341 is an equidigital number, since it uses as much as digits as its factorization.

21636341 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 26.

The square root of 21636341 is about 4651.4880414766. The cubic root of 21636341 is about 278.6514276736.

Adding to 21636341 its reverse (14363612), we get a palindrome (35999953).

The spelling of 21636341 in words is "twenty-one million, six hundred thirty-six thousand, three hundred forty-one".