284640 has 48 divisors (see below), whose sum is σ = 898128. Its totient is φ = 75776.

The previous prime is 284633. The next prime is 284651. The reversal of 284640 is 46482.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an Ulam number.

It is a d-powerful number, because it can be written as 2⁵ + 8³ + 6⁷ + 4³ + 4⁶ + 0 .

It is a self number, because there is not a number n which added to its sum of digits gives 284640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 184 + ... + 776.

It is an arithmetic number, because the mean of its divisors is an integer number (18711).

2²⁸⁴⁶⁴⁰ is an apocalyptic number.

284640 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 284640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (449064).

284640 is an abundant number, since it is smaller than the sum of its proper divisors (613488).

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

284640 is a wasteful number, since it uses less digits than its factorization.

284640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611 (or 603 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 284640 is about 533.5166351671. The cubic root of 284640 is about 65.7807231590.

The spelling of 284640 in words is "two hundred eighty-four thousand, six hundred forty".