28087386881 has 4 divisors (see below), whose sum is σ = 28152555264. Its totient is φ = 28022218500.

The previous prime is 28087386799. The next prime is 28087386923. The reversal of 28087386881 is 18868378082.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18868378082 = 2 ⋅9434189041.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28087386881 is a prime.

It is a super-2 number, since 2×28087386881² (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 28087386881.

It is not an unprimeable number, because it can be changed into a prime (28087386781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32583545 + ... + 32584406.

It is an arithmetic number, because the mean of its divisors is an integer number (7038138816).

Almost surely, 2^28087386881 is an apocalyptic number.

It is an amenable number.

28087386881 is a deficient number, since it is larger than the sum of its proper divisors (65168383).

28087386881 is an equidigital number, since it uses as much as digits as its factorization.

28087386881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65168382.

The product of its (nonzero) digits is 8257536, while the sum is 59.

The spelling of 28087386881 in words is "twenty-eight billion, eighty-seven million, three hundred eighty-six thousand, eight hundred eighty-one".