21168816 has 40 divisors (see below), whose sum is σ = 54899760. Its totient is φ = 7028736.

The previous prime is 21168803. The next prime is 21168817. The reversal of 21168816 is 61886112.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21168817) 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, 14320 + ... + 15728.

It is an arithmetic number, because the mean of its divisors is an integer number (1372494).

Almost surely, 2^21168816 is an apocalyptic number.

It is an amenable number.

21168816 is an abundant number, since it is smaller than the sum of its proper divisors (33730944).

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

21168816 is a wasteful number, since it uses less digits than its factorization.

21168816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1733 (or 1727 counting only the distinct ones).

The product of its digits is 4608, while the sum is 33.

The square root of 21168816 is about 4600.9581610791. The cubic root of 21168816 is about 276.6297320092.

The spelling of 21168816 in words is "twenty-one million, one hundred sixty-eight thousand, eight hundred sixteen".