28188617688 has 288 divisors, whose sum is σ = 100011525120. Its totient is φ = 7085232000.

The previous prime is 28188617663. The next prime is 28188617689. The reversal of 28188617688 is 88671688182.

28188617688 is a `hidden beast` number, since 2 + 8 + 1 + 8 + 8 + 617 + 6 + 8 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28188617689) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1191333 + ... + 1214763.

It is an arithmetic number, because the mean of its divisors is an integer number (347262240).

Almost surely, 2^28188617688 is an apocalyptic number.

28188617688 is a gapful number since it is divisible by the number (28) 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 28188617688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50005762560).

28188617688 is an abundant number, since it is smaller than the sum of its proper divisors (71822907432).

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

28188617688 is a wasteful number, since it uses less digits than its factorization.

28188617688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23499 (or 23485 counting only the distinct ones).

The product of its digits is 16515072, while the sum is 63.

The spelling of 28188617688 in words is "twenty-eight billion, one hundred eighty-eight million, six hundred seventeen thousand, six hundred eighty-eight".