228781 has 16 divisors (see below), whose sum is σ = 288000. Its totient is φ = 181104.

The previous prime is 228773. The next prime is 228793. The reversal of 228781 is 187822.

It is not a de Polignac number, because 228781 - 2³ = 228773 is a prime.

It is a super-2 number, since 2×228781² = 104681491922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7875 + ... + 7903.

It is an arithmetic number, because the mean of its divisors is an integer number (18000).

2²²⁸⁷⁸¹ is an apocalyptic number.

It is an amenable number.

228781 is a deficient number, since it is larger than the sum of its proper divisors (59219).

228781 is an equidigital number, since it uses as much as digits as its factorization.

228781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73 (or 59 counting only the distinct ones).

The product of its digits is 1792, while the sum is 28.

The square root of 228781 is about 478.3105685640. The cubic root of 228781 is about 61.1608226055.

The spelling of 228781 in words is "two hundred twenty-eight thousand, seven hundred eighty-one".