21004324 has 24 divisors (see below), whose sum is σ = 40860288. Its totient is φ = 9366240.

The previous prime is 21004309. The next prime is 21004331. The reversal of 21004324 is 42340012.

It is a junction number, because it is equal to n+sod(n) for n = 21004298 and 21004307.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2172 + ... + 6835.

It is an arithmetic number, because the mean of its divisors is an integer number (1702512).

Almost surely, 2^21004324 is an apocalyptic number.

It is an amenable number.

21004324 is a deficient number, since it is larger than the sum of its proper divisors (19855964).

21004324 is a wasteful number, since it uses less digits than its factorization.

21004324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9075 (or 9073 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21004324 is about 4583.0474577512. The cubic root of 21004324 is about 275.9113521928.

Adding to 21004324 its reverse (42340012), we get a palindrome (63344336).

The spelling of 21004324 in words is "twenty-one million, four thousand, three hundred twenty-four".