280500505 has 4 divisors (see below), whose sum is σ = 336600612. Its totient is φ = 224400400.

The previous prime is 280500503. The next prime is 280500511. The reversal of 280500505 is 505005082.

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 224370441 + 56130064 = 14979^2 + 7492^2 .

It is not a de Polignac number, because 280500505 - 2¹ = 280500503 is a prime.

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 280500505.

It is not an unprimeable number, because it can be changed into a prime (280500503) 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, 28050046 + ... + 28050055.

It is an arithmetic number, because the mean of its divisors is an integer number (84150153).

Almost surely, 2^280500505 is an apocalyptic number.

It is an amenable number.

280500505 is a deficient number, since it is larger than the sum of its proper divisors (56100107).

280500505 is an equidigital number, since it uses as much as digits as its factorization.

280500505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56100106.

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 280500505 is about 16748.1493007436. The cubic root of 280500505 is about 654.6028359691.

Adding to 280500505 its reverse (505005082), we get a palindrome (785505587).

The spelling of 280500505 in words is "two hundred eighty million, five hundred thousand, five hundred five".