28982281 has 4 divisors (see below), whose sum is σ = 29981700. Its totient is φ = 27982864.

The previous prime is 28982279. The next prime is 28982293. The reversal of 28982281 is 18228982.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18228982 = 2 ⋅9114491.

It can be written as a sum of positive squares in 2 ways, for example, as 5216656 + 23765625 = 2284^2 + 4875^2 .

It is a cyclic number.

It is not a de Polignac number, because 28982281 - 2¹ = 28982279 is a prime.

It is a super-2 number, since 2×28982281² = 1679945223925922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28982081) 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, 499666 + ... + 499723.

It is an arithmetic number, because the mean of its divisors is an integer number (7495425).

Almost surely, 2^28982281 is an apocalyptic number.

It is an amenable number.

28982281 is a deficient number, since it is larger than the sum of its proper divisors (999419).

28982281 is an equidigital number, since it uses as much as digits as its factorization.

28982281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999418.

The product of its digits is 36864, while the sum is 40.

The square root of 28982281 is about 5383.5193879097. The cubic root of 28982281 is about 307.1690969676.

The spelling of 28982281 in words is "twenty-eight million, nine hundred eighty-two thousand, two hundred eighty-one".