280816065 has 20 divisors (see below), whose sum is σ = 503389524. Its totient is φ = 149768352.

The previous prime is 280816061. The next prime is 280816069. The reversal of 280816065 is 560618082.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (280816061) and next prime (280816069).

It can be written as a sum of positive squares in 2 ways, for example, as 184932801 + 95883264 = 13599^2 + 9792^2 .

It is not a de Polignac number, because 280816065 - 2² = 280816061 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (280816061) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 346282 + ... + 347091.

Almost surely, 2^280816065 is an apocalyptic number.

It is an amenable number.

280816065 is a deficient number, since it is larger than the sum of its proper divisors (222573459).

280816065 is an equidigital number, since it uses as much as digits as its factorization.

280816065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693390 (or 693381 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 280816065 is about 16757.5673950607. The cubic root of 280816065 is about 654.8482176517.

The spelling of 280816065 in words is "two hundred eighty million, eight hundred sixteen thousand, sixty-five".