678021228 has 18 divisors (see below), whose sum is σ = 1713887084. Its totient is φ = 226007064.

The previous prime is 678021221. The next prime is 678021233. The reversal of 678021228 is 822120876.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 18833923 = 678021228 / (6 + 7 + 8 + 0 + 2 + 1 + 2 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 678021192 and 678021201.

It is not an unprimeable number, because it can be changed into a prime (678021221) 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 5 ways as a sum of consecutive naturals, for example, 9416926 + ... + 9416997.

Almost surely, 2^678021228 is an apocalyptic number.

It is an amenable number.

678021228 is an abundant number, since it is smaller than the sum of its proper divisors (1035865856).

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

678021228 is a wasteful number, since it uses less digits than its factorization.

678021228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18833933 (or 18833928 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 678021228 is about 26038.8407576067. The cubic root of 678021228 is about 878.5121328328.

The spelling of 678021228 in words is "six hundred seventy-eight million, twenty-one thousand, two hundred twenty-eight".