681228 has 36 divisors (see below), whose sum is σ = 1747200. Its totient is φ = 223776.

The previous prime is 681221. The next prime is 681229. The reversal of 681228 is 822186.

It is a tau number, because it is divible by the number of its divisors (36).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (681221) by changing a digit.

681228 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4498 + ... + 4646.

2⁶⁸¹²²⁸ is an apocalyptic number.

It is an amenable number.

681228 is an abundant number, since it is smaller than the sum of its proper divisors (1065972).

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

681228 is a wasteful number, since it uses less digits than its factorization.

681228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286 (or 281 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 681228 is about 825.3653736376. The cubic root of 681228 is about 87.9894959914.

It can be divided in two parts, 681 and 228, that added together give a palindrome (909).

The spelling of 681228 in words is "six hundred eighty-one thousand, two hundred twenty-eight".