228640 has 24 divisors (see below), whose sum is σ = 540540. Its totient is φ = 91392.

The previous prime is 228637. The next prime is 228647. The reversal of 228640 is 46822.

228640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 204304 + 24336 = 452^2 + 156^2 .

It is not an unprimeable number, because it can be changed into a prime (228647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 555 + ... + 874.

2²²⁸⁶⁴⁰ is an apocalyptic number.

228640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

228640 is an abundant number, since it is smaller than the sum of its proper divisors (311900).

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

228640 is a wasteful number, since it uses less digits than its factorization.

228640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1444 (or 1436 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 228640 is about 478.1631520726. The cubic root of 228640 is about 61.1482553494.

It can be divided in two parts, 228 and 640, that added together give a palindrome (868).

The spelling of 228640 in words is "two hundred twenty-eight thousand, six hundred forty".