28082881 has 4 divisors (see below), whose sum is σ = 28467652. Its totient is φ = 27698112.

The previous prime is 28082867. The next prime is 28082891. The reversal of 28082881 is 18828082.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19439281 + 8643600 = 4409^2 + 2940^2 .

It is a cyclic number.

It is not a de Polignac number, because 28082881 - 2¹³ = 28074689 is a prime.

It is a super-2 number, since 2×28082881² = 1577296410520322, which 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 28082881.

It is not an unprimeable number, because it can be changed into a prime (28082891) 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, 192276 + ... + 192421.

It is an arithmetic number, because the mean of its divisors is an integer number (7116913).

Almost surely, 2^28082881 is an apocalyptic number.

It is an amenable number.

28082881 is a deficient number, since it is larger than the sum of its proper divisors (384771).

28082881 is an equidigital number, since it uses as much as digits as its factorization.

28082881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384770.

The product of its (nonzero) digits is 16384, while the sum is 37.

The square root of 28082881 is about 5299.3283536690. The cubic root of 28082881 is about 303.9582157772.

The spelling of 28082881 in words is "twenty-eight million, eighty-two thousand, eight hundred eighty-one".