280297440 has 144 divisors (see below), whose sum is σ = 972500256. Its totient is φ = 73497600.

The previous prime is 280297429. The next prime is 280297453. The reversal of 280297440 is 44792082.

280297440 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a junction number, because it is equal to n+sod(n) for n = 280297395 and 280297404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 86245 + ... + 89435.

It is an arithmetic number, because the mean of its divisors is an integer number (6753474).

Almost surely, 2^280297440 is an apocalyptic number.

280297440 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 280297440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (486250128).

280297440 is an abundant number, since it is smaller than the sum of its proper divisors (692202816).

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

280297440 is a wasteful number, since it uses less digits than its factorization.

280297440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3273 (or 3262 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 280297440 is about 16742.0858915489. The cubic root of 280297440 is about 654.4448338594. Note that the first 3 decimals are identical.

The spelling of 280297440 in words is "two hundred eighty million, two hundred ninety-seven thousand, four hundred forty".