21216022 has 8 divisors (see below), whose sum is σ = 32684256. Its totient is φ = 10321272.

The previous prime is 21216011. The next prime is 21216047. The reversal of 21216022 is 22061212.

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 = 21215987 and 21216005.

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, 143278 + ... + 143425.

It is an arithmetic number, because the mean of its divisors is an integer number (4085532).

Almost surely, 2^21216022 is an apocalyptic number.

21216022 is a deficient number, since it is larger than the sum of its proper divisors (11468234).

21216022 is a wasteful number, since it uses less digits than its factorization.

21216022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286742.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21216022 is about 4606.0853227008. The cubic root of 21216022 is about 276.8352054495.

Adding to 21216022 its reverse (22061212), we get a palindrome (43277234).

The spelling of 21216022 in words is "twenty-one million, two hundred sixteen thousand, twenty-two".