21136424 has 32 divisors (see below), whose sum is σ = 40547520. Its totient is φ = 10327296.

The previous prime is 21136403. The next prime is 21136429. The reversal of 21136424 is 42463112.

It is a self number, because there is not a number n which added to its sum of digits gives 21136424.

It is not an unprimeable number, because it can be changed into a prime (21136429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 92999 + ... + 93225.

It is an arithmetic number, because the mean of its divisors is an integer number (1267110).

Almost surely, 2^21136424 is an apocalyptic number.

It is an amenable number.

21136424 is a deficient number, since it is larger than the sum of its proper divisors (19411096).

21136424 is a wasteful number, since it uses less digits than its factorization.

21136424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449 (or 445 counting only the distinct ones).

The product of its digits is 1152, while the sum is 23.

The square root of 21136424 is about 4597.4366771061. The cubic root of 21136424 is about 276.4885626496.

Adding to 21136424 its reverse (42463112), we get a palindrome (63599536).

The spelling of 21136424 in words is "twenty-one million, one hundred thirty-six thousand, four hundred twenty-four".