21608000 has 112 divisors (see below), whose sum is σ = 55711344. Its totient is φ = 8294400.

The previous prime is 21607991. The next prime is 21608029. The reversal of 21608000 is 80612.

It can be written as a sum of positive squares in 8 ways, for example, as 2458624 + 19149376 = 1568^2 + 4376^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21608000.

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, 295964 + ... + 296036.

Almost surely, 2^21608000 is an apocalyptic number.

21608000 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 21608000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27855672).

21608000 is an abundant number, since it is smaller than the sum of its proper divisors (34103344).

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

21608000 is an equidigital number, since it uses as much as digits as its factorization.

21608000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 21608000 is about 4648.4405987385. The cubic root of 21608000 is about 278.5297079124.

Adding to 21608000 its reverse (80612), we get a palindrome (21688612).

The spelling of 21608000 in words is "twenty-one million, six hundred eight thousand".