280028005 has 4 divisors (see below), whose sum is σ = 336033612. Its totient is φ = 224022400.

The previous prime is 280027981. The next prime is 280028009. The reversal of 280028005 is 500820082.

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 181899169 + 98128836 = 13487^2 + 9906^2 .

It is not a de Polignac number, because 280028005 - 2¹¹ = 280025957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280028009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28002796 + ... + 28002805.

It is an arithmetic number, because the mean of its divisors is an integer number (84008403).

Almost surely, 2^280028005 is an apocalyptic number.

It is an amenable number.

280028005 is a deficient number, since it is larger than the sum of its proper divisors (56005607).

280028005 is an equidigital number, since it uses as much as digits as its factorization.

280028005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56005606.

The product of its (nonzero) digits is 1280, while the sum is 25.

The square root of 280028005 is about 16734.0373191887. The cubic root of 280028005 is about 654.2350723135.

Adding to 280028005 its reverse (500820082), we get a palindrome (780848087).

The spelling of 280028005 in words is "two hundred eighty million, twenty-eight thousand, five".