21325724 has 12 divisors (see below), whose sum is σ = 42651504. Its totient is φ = 9139584.

The previous prime is 21325693. The next prime is 21325739. The reversal of 21325724 is 42752312.

21325724 is an admirable number.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 21325693 and 21325702.

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, 380789 + ... + 380844.

It is an arithmetic number, because the mean of its divisors is an integer number (3554292).

Almost surely, 2^21325724 is an apocalyptic number.

It is an amenable number.

21325724 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21325724 is a wasteful number, since it uses less digits than its factorization.

21325724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761644 (or 761642 counting only the distinct ones).

The product of its digits is 3360, while the sum is 26.

The square root of 21325724 is about 4617.9783455534. The cubic root of 21325724 is about 277.3115307123.

The spelling of 21325724 in words is "twenty-one million, three hundred twenty-five thousand, seven hundred twenty-four".