280285920 has 240 divisors, whose sum is σ = 1004406480. Its totient is φ = 73903104.

The previous prime is 280285913. The next prime is 280285961. The reversal of 280285920 is 29582082.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3149236 + ... + 3149324.

It is an arithmetic number, because the mean of its divisors is an integer number (4185027).

Almost surely, 2^280285920 is an apocalyptic number.

280285920 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 280285920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (502203240).

280285920 is an abundant number, since it is smaller than the sum of its proper divisors (724120560).

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

280285920 is an frugal number, since it uses more digits than its factorization.

280285920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 280285920 is about 16741.7418448619. The cubic root of 280285920 is about 654.4358680173.

The spelling of 280285920 in words is "two hundred eighty million, two hundred eighty-five thousand, nine hundred twenty".