280640216 has 32 divisors (see below), whose sum is σ = 562697280. Its totient is φ = 130752000.

The previous prime is 280640207. The next prime is 280640249. The reversal of 280640216 is 612046082.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3521 + ... + 23951.

It is an arithmetic number, because the mean of its divisors is an integer number (17584290).

Almost surely, 2^280640216 is an apocalyptic number.

It is an amenable number.

280640216 is an abundant number, since it is smaller than the sum of its proper divisors (282057064).

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

280640216 is a wasteful number, since it uses less digits than its factorization.

280640216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20555 (or 20551 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 280640216 is about 16752.3197199671. The cubic root of 280640216 is about 654.7114989192.

Adding to 280640216 its reverse (612046082), we get a palindrome (892686298).

The spelling of 280640216 in words is "two hundred eighty million, six hundred forty thousand, two hundred sixteen".