280561000 has 32 divisors (see below), whose sum is σ = 656515080. Its totient is φ = 112224000.

The previous prime is 280560971. The next prime is 280561009. The reversal of 280561000 is 165082.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 10484644 + 270076356 = 3238^2 + 16434^2 .

It is not an unprimeable number, because it can be changed into a prime (280561009) 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 7 ways as a sum of consecutive naturals, for example, 139281 + ... + 141280.

Almost surely, 2^280561000 is an apocalyptic number.

280561000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

280561000 is an abundant number, since it is smaller than the sum of its proper divisors (375954080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

280561000 is a wasteful number, since it uses less digits than its factorization.

280561000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280582 (or 280568 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 280561000 is about 16749.9552238207. The cubic root of 280561000 is about 654.6498915613.

The spelling of 280561000 in words is "two hundred eighty million, five hundred sixty-one thousand".