280000000 has 160 divisors (see below), whose sum is σ = 799216704. Its totient is φ = 96000000.

The previous prime is 279999991. The next prime is 280000027. The reversal of 280000000 is 82.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39999997 + ... + 40000003.

Almost surely, 2^280000000 is an apocalyptic number.

280000000 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 280000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (399608352).

280000000 is an abundant number, since it is smaller than the sum of its proper divisors (519216704).

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

280000000 is an frugal number, since it uses more digits than its factorization.

280000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60 (or 14 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 280000000 is about 16733.2005306815. The cubic root of 280000000 is about 654.2132620377.

Adding to 280000000 its reverse (82), we get a palindrome (280000082).

The spelling of 280000000 in words is "two hundred eighty million", and thus it is an aban number.