285387840 has 448 divisors, whose sum is σ = 1119225600. Its totient is φ = 68124672.

The previous prime is 285387827. The next prime is 285387853. The reversal of 285387840 is 48783582.

285387840 is a `hidden beast` number, since 2 + 8 + 538 + 78 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (285387827) and next prime (285387853).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4259487 + ... + 4259553.

Almost surely, 2^285387840 is an apocalyptic number.

285387840 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 285387840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (559612800).

285387840 is an abundant number, since it is smaller than the sum of its proper divisors (833837760).

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

285387840 is a wasteful number, since it uses less digits than its factorization.

285387840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 123 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 45.

The square root of 285387840 is about 16893.4259402881. The cubic root of 285387840 is about 658.3828175519.

The spelling of 285387840 in words is "two hundred eighty-five million, three hundred eighty-seven thousand, eight hundred forty".