285780240 has 120 divisors (see below), whose sum is σ = 977984280. Its totient is φ = 74760192.

The previous prime is 285780203. The next prime is 285780241. The reversal of 285780240 is 42087582.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 51322896 + 234457344 = 7164^2 + 15312^2 .

It is a tau number, because it is divible by the number of its divisors (120).

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 = 285780195 and 285780204.

It is not an unprimeable number, because it can be changed into a prime (285780241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34416 + ... + 41904.

It is an arithmetic number, because the mean of its divisors is an integer number (8149869).

Almost surely, 2^285780240 is an apocalyptic number.

285780240 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 285780240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (488992140).

285780240 is an abundant number, since it is smaller than the sum of its proper divisors (692204040).

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

285780240 is a wasteful number, since it uses less digits than its factorization.

285780240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7561 (or 7552 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 36.

The square root of 285780240 is about 16905.0359360754. The cubic root of 285780240 is about 658.6844317813.

The spelling of 285780240 in words is "two hundred eighty-five million, seven hundred eighty thousand, two hundred forty".