21330524 has 12 divisors (see below), whose sum is σ = 37367400. Its totient is φ = 10654128.

The previous prime is 21330503. The next prime is 21330581. The reversal of 21330524 is 42503312.

It is a happy number.

It is a super-2 number, since 2×21330524² = 909982508229152, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21330496 and 21330505.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2747 + ... + 7085.

It is an arithmetic number, because the mean of its divisors is an integer number (3113950).

Almost surely, 2^21330524 is an apocalyptic number.

It is an amenable number.

21330524 is a deficient number, since it is larger than the sum of its proper divisors (16036876).

21330524 is a wasteful number, since it uses less digits than its factorization.

21330524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5572 (or 5570 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 21330524 is about 4618.4980242499. The cubic root of 21330524 is about 277.3323349374.

Adding to 21330524 its reverse (42503312), we get a palindrome (63833836).

The spelling of 21330524 in words is "twenty-one million, three hundred thirty thousand, five hundred twenty-four".