21404522 has 8 divisors (see below), whose sum is σ = 32148900. Its totient is φ = 10688224.

The previous prime is 21404503. The next prime is 21404531. The reversal of 21404522 is 22540412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14753281 + 6651241 = 3841^2 + 2579^2 .

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 = 21404494 and 21404503.

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, 4997 + ... + 8232.

Almost surely, 2^21404522 is an apocalyptic number.

21404522 is a deficient number, since it is larger than the sum of its proper divisors (10744378).

21404522 is a wasteful number, since it uses less digits than its factorization.

21404522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14040.

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

The square root of 21404522 is about 4626.5021344424. The cubic root of 21404522 is about 277.6526638811.

Adding to 21404522 its reverse (22540412), we get a palindrome (43944934).

The spelling of 21404522 in words is "twenty-one million, four hundred four thousand, five hundred twenty-two".