21412816 has 40 divisors (see below), whose sum is σ = 44711424. Its totient is φ = 9905280.

The previous prime is 21412801. The next prime is 21412823. The reversal of 21412816 is 61821412.

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 7 ways as a sum of consecutive naturals, for example, 10470 + ... + 12346.

Almost surely, 2^21412816 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 21412816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22355712).

21412816 is an abundant number, since it is smaller than the sum of its proper divisors (23298608).

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

21412816 is a wasteful number, since it uses less digits than its factorization.

21412816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1939 (or 1933 counting only the distinct ones).

The product of its digits is 768, while the sum is 25.

The square root of 21412816 is about 4627.3984051516. The cubic root of 21412816 is about 277.6885216283.

The spelling of 21412816 in words is "twenty-one million, four hundred twelve thousand, eight hundred sixteen".