21600000000 has 432 divisors, whose sum is σ = 79980427800. Its totient is φ = 5760000000.

The previous prime is 21599999969. The next prime is 21600000017. The reversal of 21600000000 is 612.

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.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4319999998 + ... + 4320000002.

Almost surely, 2^21600000000 is an apocalyptic number.

21600000000 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 21600000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39990213900).

21600000000 is an abundant number, since it is smaller than the sum of its proper divisors (58380427800).

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

21600000000 is an frugal number, since it uses more digits than its factorization.

21600000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71 (or 10 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

Adding to 21600000000 its reverse (612), we get a palindrome (21600000612).

The spelling of 21600000000 in words is "twenty-one billion, six hundred million", and thus it is an aban number.