21636124 has 6 divisors (see below), whose sum is σ = 37863224. Its totient is φ = 10818060.

The previous prime is 21636107. The next prime is 21636143. The reversal of 21636124 is 42163612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2704512 + ... + 2704519.

Almost surely, 2^21636124 is an apocalyptic number.

It is an amenable number.

21636124 is a deficient number, since it is larger than the sum of its proper divisors (16227100).

21636124 is a wasteful number, since it uses less digits than its factorization.

21636124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5409035 (or 5409033 counting only the distinct ones).

The product of its digits is 1728, while the sum is 25.

The square root of 21636124 is about 4651.4647155493. The cubic root of 21636124 is about 278.6504960995.

Adding to 21636124 its reverse (42163612), we get a palindrome (63799736).

The spelling of 21636124 in words is "twenty-one million, six hundred thirty-six thousand, one hundred twenty-four".