28390997181888 has 560 divisors, whose sum is σ = 94029771141504. Its totient is φ = 8395748444160.

The previous prime is 28390997181847. The next prime is 28390997181889. The reversal of 28390997181888 is 88818179909382.

28390997181888 is a `hidden beast` number, since 2 + 8 + 390 + 9 + 9 + 71 + 81 + 8 + 88 = 666.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28390997181889) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 3131240331 + ... + 3131249397.

Almost surely, 2^{28390997181888} 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 28390997181888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47014885570752).

28390997181888 is an abundant number, since it is smaller than the sum of its proper divisors (65638773959616).

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

28390997181888 is a wasteful number, since it uses less digits than its factorization.

28390997181888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10422 (or 10403 counting only the distinct ones).

The product of its (nonzero) digits is 1003290624, while the sum is 81.

The spelling of 28390997181888 in words is "twenty-eight trillion, three hundred ninety billion, nine hundred ninety-seven million, one hundred eighty-one thousand, eight hundred eighty-eight".