21453136 has 20 divisors (see below), whose sum is σ = 41639200. Its totient is φ = 10707552.

The previous prime is 21453119. The next prime is 21453143. The reversal of 21453136 is 63135412.

It is a self number, because there is not a number n which added to its sum of digits gives 21453136.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13975 + ... + 15433.

It is an arithmetic number, because the mean of its divisors is an integer number (2081960).

Almost surely, 2^21453136 is an apocalyptic number.

It is an amenable number.

21453136 is a deficient number, since it is larger than the sum of its proper divisors (20186064).

21453136 is a wasteful number, since it uses less digits than its factorization.

21453136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2386 (or 2380 counting only the distinct ones).

The product of its digits is 2160, while the sum is 25.

The square root of 21453136 is about 4631.7530158678. The cubic root of 21453136 is about 277.8627067360.

Adding to 21453136 its reverse (63135412), we get a palindrome (84588548).

The spelling of 21453136 in words is "twenty-one million, four hundred fifty-three thousand, one hundred thirty-six".