21504422 has 8 divisors (see below), whose sum is σ = 34154136. Its totient is φ = 10119712.

The previous prime is 21504403. The next prime is 21504433. The reversal of 21504422 is 22440512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21504394 and 21504403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 316208 + ... + 316275.

It is an arithmetic number, because the mean of its divisors is an integer number (4269267).

Almost surely, 2^21504422 is an apocalyptic number.

21504422 is a deficient number, since it is larger than the sum of its proper divisors (12649714).

21504422 is a wasteful number, since it uses less digits than its factorization.

21504422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632502.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 21504422 is about 4637.2860597552. The cubic root of 21504422 is about 278.0839506307.

Adding to 21504422 its reverse (22440512), we get a palindrome (43944934).

The spelling of 21504422 in words is "twenty-one million, five hundred four thousand, four hundred twenty-two".