21384524 has 24 divisors (see below), whose sum is σ = 43411200. Its totient is φ = 9027216.

The previous prime is 21384511. The next prime is 21384529. The reversal of 21384524 is 42548312.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21384529) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 3824 + ... + 7575.

It is an arithmetic number, because the mean of its divisors is an integer number (1808800).

Almost surely, 2^21384524 is an apocalyptic number.

It is an amenable number.

21384524 is an abundant number, since it is smaller than the sum of its proper divisors (22026676).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21384524 is a wasteful number, since it uses less digits than its factorization.

21384524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11477 (or 11475 counting only the distinct ones).

The product of its digits is 7680, while the sum is 29.

The square root of 21384524 is about 4624.3403853955. The cubic root of 21384524 is about 277.5661677024.

The spelling of 21384524 in words is "twenty-one million, three hundred eighty-four thousand, five hundred twenty-four".