21728476800 has 288 divisors, whose sum is σ = 80406624480. Its totient is φ = 5794053120.

The previous prime is 21728476771. The next prime is 21728476811. The reversal of 21728476800 is 867482712.

21728476800 is a `hidden beast` number, since 2 + 172 + 8 + 476 + 8 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 763629 + ... + 791571.

Almost surely, 2^21728476800 is an apocalyptic number.

21728476800 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 21728476800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40203312240).

21728476800 is an abundant number, since it is smaller than the sum of its proper divisors (58678147680).

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

21728476800 is an equidigital number, since it uses as much as digits as its factorization.

21728476800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27982 (or 27953 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 45.

The spelling of 21728476800 in words is "twenty-one billion, seven hundred twenty-eight million, four hundred seventy-six thousand, eight hundred".