21316000 has 72 divisors (see below), whose sum is σ = 53100684. Its totient is φ = 8409600.

The previous prime is 21315997. The next prime is 21316021. The reversal of 21316000 is 61312.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

21316000 is nontrivially palindromic in base 3 and base 9.

It can be written as a sum of positive squares in 6 ways, for example, as 1281424 + 20034576 = 1132^2 + 4476^2 .

It is a zygodrome in base 3.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 291964 + ... + 292036.

Almost surely, 2^21316000 is an apocalyptic number.

21316000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21316000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26550342).

21316000 is an abundant number, since it is smaller than the sum of its proper divisors (31784684).

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

21316000 is an frugal number, since it uses more digits than its factorization.

21316000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 80 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21316000 is about 4616.9253838458. The cubic root of 21316000 is about 277.2693752496.

Adding to 21316000 its reverse (61312), we get a palindrome (21377312).

The spelling of 21316000 in words is "twenty-one million, three hundred sixteen thousand".