28182281 has 4 divisors (see below), whose sum is σ = 28781952. Its totient is φ = 27582612.

The previous prime is 28182247. The next prime is 28182367. The reversal of 28182281 is 18228182.

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 a cyclic number.

It is not a de Polignac number, because 28182281 - 2¹⁴ = 28165897 is a prime.

It is a super-2 number, since 2×28182281² = 1588481924725922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28182221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 299765 + ... + 299858.

It is an arithmetic number, because the mean of its divisors is an integer number (7195488).

Almost surely, 2^28182281 is an apocalyptic number.

It is an amenable number.

28182281 is a deficient number, since it is larger than the sum of its proper divisors (599671).

28182281 is an equidigital number, since it uses as much as digits as its factorization.

28182281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599670.

The product of its digits is 4096, while the sum is 32.

The square root of 28182281 is about 5308.6986164219. The cubic root of 28182281 is about 304.3164158436.

The spelling of 28182281 in words is "twenty-eight million, one hundred eighty-two thousand, two hundred eighty-one".