280266640 has 80 divisors (see below), whose sum is σ = 671742720. Its totient is φ = 108692480.

The previous prime is 280266631. The next prime is 280266677. The reversal of 280266640 is 46662082.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 280266596 and 280266605.

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 15 ways as a sum of consecutive naturals, for example, 492276 + ... + 492844.

It is an arithmetic number, because the mean of its divisors is an integer number (8396784).

Almost surely, 2^280266640 is an apocalyptic number.

280266640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 280266640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (335871360).

280266640 is an abundant number, since it is smaller than the sum of its proper divisors (391476080).

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

280266640 is a wasteful number, since it uses less digits than its factorization.

280266640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760 (or 754 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 280266640 is about 16741.1660286851. The cubic root of 280266640 is about 654.4208621346.

The spelling of 280266640 in words is "two hundred eighty million, two hundred sixty-six thousand, six hundred forty".