280216656 has 60 divisors (see below), whose sum is σ = 786720480. Its totient is φ = 93107520.

The previous prime is 280216639. The next prime is 280216663. The reversal of 280216656 is 656612082.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 280216656.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 44725 + ... + 50603.

It is an arithmetic number, because the mean of its divisors is an integer number (13112008).

Almost surely, 2^280216656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 280216656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (393360240).

280216656 is an abundant number, since it is smaller than the sum of its proper divisors (506503824).

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

280216656 is a wasteful number, since it uses less digits than its factorization.

280216656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6224 (or 6215 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 280216656 is about 16739.6731150880. The cubic root of 280216656 is about 654.3819557119.

The spelling of 280216656 in words is "two hundred eighty million, two hundred sixteen thousand, six hundred fifty-six".