21017328000 has 128 divisors (see below), whose sum is σ = 69672601440. Its totient is φ = 5604608000.

The previous prime is 21017327971. The next prime is 21017328001. The reversal of 21017328000 is 82371012.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21017328001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 170931 + ... + 266930.

Almost surely, 2^21017328000 is an apocalyptic number.

21017328000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21017328000 is an abundant number, since it is smaller than the sum of its proper divisors (48655273440).

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

21017328000 is an equidigital number, since it uses as much as digits as its factorization.

21017328000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437893 (or 437871 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

Adding to 21017328000 its reverse (82371012), we get a palindrome (21099699012).

The spelling of 21017328000 in words is "twenty-one billion, seventeen million, three hundred twenty-eight thousand".