280813500 has 384 divisors, whose sum is σ = 1039933440. Its totient is φ = 64800000.

The previous prime is 280813493. The next prime is 280813501. The reversal of 280813500 is 5318082.

It is a happy number.

280813500 is a `hidden beast` number, since 2 + 80 + 81 + 3 + 500 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280813501) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4603470 + ... + 4603530.

It is an arithmetic number, because the mean of its divisors is an integer number (2708160).

Almost surely, 2^280813500 is an apocalyptic number.

280813500 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 280813500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (519966720).

280813500 is an abundant number, since it is smaller than the sum of its proper divisors (759119940).

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

280813500 is a wasteful number, since it uses less digits than its factorization.

280813500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 280813500 is about 16757.4908622980. The cubic root of 280813500 is about 654.8462238308.

The spelling of 280813500 in words is "two hundred eighty million, eight hundred thirteen thousand, five hundred".