21636107 has 2 divisors, whose sum is σ = 21636108. Its totient is φ = 21636106.

The previous prime is 21636089. The next prime is 21636143. The reversal of 21636107 is 70163612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21636107 - 2²⁰ = 20587531 is a prime.

It is a super-2 number, since 2×21636107² = 936242252230898, which contains 22 as substring.

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

It is not a weakly prime, because it can be changed into another prime (21636187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10818053 + 10818054.

It is an arithmetic number, because the mean of its divisors is an integer number (10818054).

Almost surely, 2^21636107 is an apocalyptic number.

21636107 is a deficient number, since it is larger than the sum of its proper divisors (1).

21636107 is an equidigital number, since it uses as much as digits as its factorization.

21636107 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 21636107 is about 4651.4628881675. The cubic root of 21636107 is about 278.6504231188.

Adding to 21636107 its reverse (70163612), we get a palindrome (91799719).

The spelling of 21636107 in words is "twenty-one million, six hundred thirty-six thousand, one hundred seven".