21636135 has 12 divisors (see below), whose sum is σ = 37502712. Its totient is φ = 11539248.

The previous prime is 21636107. The next prime is 21636143. The reversal of 21636135 is 53163612.

21636135 is a `hidden beast` number, since 21 + 636 + 1 + 3 + 5 = 666.

It is not a de Polignac number, because 21636135 - 2⁷ = 21636007 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21636099 and 21636108.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 240357 + ... + 240446.

It is an arithmetic number, because the mean of its divisors is an integer number (3125226).

Almost surely, 2^21636135 is an apocalyptic number.

21636135 is a deficient number, since it is larger than the sum of its proper divisors (15866577).

21636135 is a wasteful number, since it uses less digits than its factorization.

21636135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480814 (or 480811 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 21636135 is about 4651.4658979724. The cubic root of 21636135 is about 278.6505433223.

Adding to 21636135 its reverse (53163612), we get a palindrome (74799747).

The spelling of 21636135 in words is "twenty-one million, six hundred thirty-six thousand, one hundred thirty-five".