28881784881 has 12 divisors (see below), whose sum is σ = 41738207940. Its totient is φ = 19245258240.

The previous prime is 28881784873. The next prime is 28881784909. The reversal of 28881784881 is 18848718882.

28881784881 is a `hidden beast` number, since 2 + 8 + 8 + 81 + 78 + 488 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 22052250000 + 6829534881 = 148500^2 + 82641^2 .

It is not a de Polignac number, because 28881784881 - 2³ = 28881784873 is a prime.

It is a super-2 number, since 2×28881784881² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28881784681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 752316 + ... + 789773.

It is an arithmetic number, because the mean of its divisors is an integer number (3478183995).

Almost surely, 2^28881784881 is an apocalyptic number.

It is an amenable number.

28881784881 is a deficient number, since it is larger than the sum of its proper divisors (12856423059).

28881784881 is a wasteful number, since it uses less digits than its factorization.

28881784881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1544176 (or 1544173 counting only the distinct ones).

The product of its digits is 14680064, while the sum is 63.

The spelling of 28881784881 in words is "twenty-eight billion, eight hundred eighty-one million, seven hundred eighty-four thousand, eight hundred eighty-one".