21728124328680 has 192 divisors, whose sum is σ = 88041231158400. Its totient is φ = 4514934919680.

The previous prime is 21728124328637. The next prime is 21728124328693. The reversal of 21728124328680 is 8682342182712.

It is a happy number.

21728124328680 is a `hidden beast` number, since 2 + 1 + 7 + 281 + 2 + 4 + 3 + 286 + 80 = 666.

It is a super-2 number, since 2×21728124328680² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 391893715 + ... + 391949154.

It is an arithmetic number, because the mean of its divisors is an integer number (458548078950).

Almost surely, 2^{21728124328680} is an apocalyptic number.

21728124328680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21728124328680 is an abundant number, since it is smaller than the sum of its proper divisors (66313106829720).

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

21728124328680 is a wasteful number, since it uses less digits than its factorization.

21728124328680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783842904 (or 783842897 counting only the distinct ones).

The product of its (nonzero) digits is 4128768, while the sum is 54.

The spelling of 21728124328680 in words is "twenty-one trillion, seven hundred twenty-eight billion, one hundred twenty-four million, three hundred twenty-eight thousand, six hundred eighty".