21422016 has 336 divisors, whose sum is σ = 83393280. Its totient is φ = 5322240.

The previous prime is 21421997. The next prime is 21422021. The reversal of 21422016 is 61022412.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 21422016.

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 47 ways as a sum of consecutive naturals, for example, 931381 + ... + 931403.

Almost surely, 2^21422016 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21422016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41696640).

21422016 is an abundant number, since it is smaller than the sum of its proper divisors (61971264).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21422016 is a wasteful number, since it uses less digits than its factorization.

21422016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21422016 is about 4628.3923774892. The cubic root of 21422016 is about 277.7282854876.

Adding to 21422016 its reverse (61022412), we get a palindrome (82444428).

The spelling of 21422016 in words is "twenty-one million, four hundred twenty-two thousand, sixteen".