280805005 has 16 divisors (see below), whose sum is σ = 363255984. Its totient is φ = 207152640.

The previous prime is 280805003. The next prime is 280805011. The reversal of 280805005 is 500508082.

It can be written as a sum of positive squares in 8 ways, for example, as 1447209 + 279357796 = 1203^2 + 16714^2 .

It is not a de Polignac number, because 280805005 - 2¹ = 280805003 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280805003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94807 + ... + 97723.

It is an arithmetic number, because the mean of its divisors is an integer number (22703499).

Almost surely, 2^280805005 is an apocalyptic number.

It is an amenable number.

280805005 is a deficient number, since it is larger than the sum of its proper divisors (82450979).

280805005 is a wasteful number, since it uses less digits than its factorization.

280805005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4416.

The product of its (nonzero) digits is 3200, while the sum is 28.

The square root of 280805005 is about 16757.2373916466. The cubic root of 280805005 is about 654.8396204271.

The spelling of 280805005 in words is "two hundred eighty million, eight hundred five thousand, five".