28135228881 has 4 divisors (see below), whose sum is σ = 37513638512. Its totient is φ = 18756819252.

The previous prime is 28135228873. The next prime is 28135228889. The reversal of 28135228881 is 18882253182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (28135228873) and next prime (28135228889).

It is not a de Polignac number, because 28135228881 - 2³ = 28135228873 is a prime.

It is a super-2 number, since 2×28135228881² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28135228881.

It is not an unprimeable number, because it can be changed into a prime (28135228889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4689204811 + ... + 4689204816.

It is an arithmetic number, because the mean of its divisors is an integer number (9378409628).

Almost surely, 2^28135228881 is an apocalyptic number.

It is an amenable number.

28135228881 is a deficient number, since it is larger than the sum of its proper divisors (9378409631).

28135228881 is an equidigital number, since it uses as much as digits as its factorization.

28135228881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9378409630.

The product of its digits is 491520, while the sum is 48.

The spelling of 28135228881 in words is "twenty-eight billion, one hundred thirty-five million, two hundred twenty-eight thousand, eight hundred eighty-one".