21016416 has 48 divisors (see below), whose sum is σ = 57078000. Its totient is φ = 6763008.

The previous prime is 21016409. The next prime is 21016417. The reversal of 21016416 is 61461012.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 21016392 and 21016401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21016417) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 991 + ... + 6558.

It is an arithmetic number, because the mean of its divisors is an integer number (1189125).

Almost surely, 2^21016416 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 21016416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28539000).

21016416 is an abundant number, since it is smaller than the sum of its proper divisors (36061584).

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

21016416 is a wasteful number, since it uses less digits than its factorization.

21016416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7591 (or 7583 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21016416 is about 4584.3664774972. The cubic root of 21016416 is about 275.9642885952.

Adding to 21016416 its reverse (61461012), we get a palindrome (82477428).

The spelling of 21016416 in words is "twenty-one million, sixteen thousand, four hundred sixteen".