21730504 has 16 divisors (see below), whose sum is σ = 42059520. Its totient is φ = 10514640.

The previous prime is 21730493. The next prime is 21730517. The reversal of 21730504 is 40503712.

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, 43564 + ... + 44059.

It is an arithmetic number, because the mean of its divisors is an integer number (2628720).

Almost surely, 2^21730504 is an apocalyptic number.

It is an amenable number.

21730504 is a deficient number, since it is larger than the sum of its proper divisors (20329016).

21730504 is a wasteful number, since it uses less digits than its factorization.

21730504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87660 (or 87656 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 21730504 is about 4661.5988673415. The cubic root of 21730504 is about 279.0550800586.

The spelling of 21730504 in words is "twenty-one million, seven hundred thirty thousand, five hundred four".