280490820 has 96 divisors (see below), whose sum is σ = 843187968. Its totient is φ = 69414912.

The previous prime is 280490809. The next prime is 280490827. The reversal of 280490820 is 28094082.

280490820 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (280490827) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 72577 + ... + 76343.

It is an arithmetic number, because the mean of its divisors is an integer number (8783208).

Almost surely, 2^280490820 is an apocalyptic number.

280490820 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 280490820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (421593984).

280490820 is an abundant number, since it is smaller than the sum of its proper divisors (562697148).

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

280490820 is a wasteful number, since it uses less digits than its factorization.

280490820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3869 (or 3867 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 280490820 is about 16747.8601618237. The cubic root of 280490820 is about 654.5953019347.

The spelling of 280490820 in words is "two hundred eighty million, four hundred ninety thousand, eight hundred twenty".