28605236881 has 32 divisors (see below), whose sum is σ = 33522128640. Its totient is φ = 24167614464.

The previous prime is 28605236819. The next prime is 28605236899. The reversal of 28605236881 is 18863250682.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28605236881 is a prime.

It is a super-2 number, since 2×28605236881² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (28605236381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2207740 + ... + 2220658.

It is an arithmetic number, because the mean of its divisors is an integer number (1047566520).

Almost surely, 2^28605236881 is an apocalyptic number.

It is an amenable number.

28605236881 is a deficient number, since it is larger than the sum of its proper divisors (4916891759).

28605236881 is a wasteful number, since it uses less digits than its factorization.

28605236881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13225.

The product of its (nonzero) digits is 1105920, while the sum is 49.

The spelling of 28605236881 in words is "twenty-eight billion, six hundred five million, two hundred thirty-six thousand, eight hundred eighty-one".