28156197888 has 1056 divisors, whose sum is σ = 111807467520. Its totient is φ = 6808043520.

The previous prime is 28156197863. The next prime is 28156197889. The reversal of 28156197888 is 88879165182.

28156197888 is a `hidden beast` number, since 2 + 8 + 1 + 5 + 619 + 7 + 8 + 8 + 8 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28156197889) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 908264433 + ... + 908264463.

Almost surely, 2^28156197888 is an apocalyptic number.

28156197888 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 28156197888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55903733760).

28156197888 is an abundant number, since it is smaller than the sum of its proper divisors (83651269632).

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

28156197888 is a wasteful number, since it uses less digits than its factorization.

28156197888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118 (or 75 counting only the distinct ones).

The product of its digits is 15482880, while the sum is 63.

The spelling of 28156197888 in words is "twenty-eight billion, one hundred fifty-six million, one hundred ninety-seven thousand, eight hundred eighty-eight".