28020617856 has 288 divisors, whose sum is σ = 102325934880. Its totient is φ = 7277921280.

The previous prime is 28020617843. The next prime is 28020617857. The reversal of 28020617856 is 65871602082.

28020617856 is a `hidden beast` number, since 2 + 8 + 0 + 20 + 617 + 8 + 5 + 6 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (28020617857) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 598365 + ... + 643491.

It is an arithmetic number, because the mean of its divisors is an integer number (355298385).

Almost surely, 2^28020617856 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 28020617856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51162967440).

28020617856 is an abundant number, since it is smaller than the sum of its proper divisors (74305317024).

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

28020617856 is a wasteful number, since it uses less digits than its factorization.

28020617856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45172 (or 45150 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The spelling of 28020617856 in words is "twenty-eight billion, twenty million, six hundred seventeen thousand, eight hundred fifty-six".