21716000 has 96 divisors (see below), whose sum is σ = 54840240. Its totient is φ = 8448000.

The previous prime is 21715999. The next prime is 21716017. The reversal of 21716000 is 61712.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1752976 + 19963024 = 1324^2 + 4468^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21716000.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 243956 + ... + 244044.

Almost surely, 2^21716000 is an apocalyptic number.

21716000 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 21716000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27420120).

21716000 is an abundant number, since it is smaller than the sum of its proper divisors (33124240).

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

21716000 is an equidigital number, since it uses as much as digits as its factorization.

21716000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 21716000 is about 4660.0429182573. The cubic root of 21716000 is about 278.9929812428.

Adding to 21716000 its reverse (61712), we get a palindrome (21777712).

The spelling of 21716000 in words is "twenty-one million, seven hundred sixteen thousand".