21728040417792 has 1280 divisors, whose sum is σ = 72931107110400. Its totient is φ = 6354810961920.

The previous prime is 21728040417791. The next prime is 21728040417793. The reversal of 21728040417792 is 29771404082712.

It is a happy number.

21728040417792 is a `hidden beast` number, since 2 + 1 + 7 + 2 + 80 + 404 + 1 + 77 + 92 = 666.

It is an interprime number because it is at equal distance from previous prime (21728040417791) and next prime (21728040417793).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (21728040417791) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 21033920508 + ... + 21033921540.

It is an arithmetic number, because the mean of its divisors is an integer number (56977427430).

Almost surely, 2^{21728040417792} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21728040417792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36465553555200).

21728040417792 is an abundant number, since it is smaller than the sum of its proper divisors (51203066692608).

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

21728040417792 is a wasteful number, since it uses less digits than its factorization.

21728040417792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1214 (or 1192 counting only the distinct ones).

The product of its (nonzero) digits is 3161088, while the sum is 54.

The spelling of 21728040417792 in words is "twenty-one trillion, seven hundred twenty-eight billion, forty million, four hundred seventeen thousand, seven hundred ninety-two".