21716016 has 80 divisors (see below), whose sum is σ = 65472000. Its totient is φ = 6199872.

The previous prime is 21715999. The next prime is 21716017. The reversal of 21716016 is 61061712.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21716017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15805 + ... + 17123.

It is an arithmetic number, because the mean of its divisors is an integer number (818400).

Almost surely, 2^21716016 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 21716016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32736000).

21716016 is an abundant number, since it is smaller than the sum of its proper divisors (43755984).

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

21716016 is a wasteful number, since it uses less digits than its factorization.

21716016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1351 (or 1331 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 21716016 is about 4660.0446349794. The cubic root of 21716016 is about 278.9930497620.

Adding to 21716016 its reverse (61061712), we get a palindrome (82777728).

The spelling of 21716016 in words is "twenty-one million, seven hundred sixteen thousand, sixteen".