644341228 has 24 divisors (see below), whose sum is σ = 1177531488. Its totient is φ = 307925376.

The previous prime is 644341223. The next prime is 644341237. The reversal of 644341228 is 822143446.

It is a junction number, because it is equal to n+sod(n) for n = 644341193 and 644341202.

It is not an unprimeable number, because it can be changed into a prime (644341223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196450 + ... + 199702.

It is an arithmetic number, because the mean of its divisors is an integer number (49063812).

Almost surely, 2^644341228 is an apocalyptic number.

It is an amenable number.

644341228 is a deficient number, since it is larger than the sum of its proper divisors (533190260).

644341228 is a wasteful number, since it uses less digits than its factorization.

644341228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5433 (or 5431 counting only the distinct ones).

The product of its digits is 36864, while the sum is 34.

The square root of 644341228 is about 25383.8773240023. The cubic root of 644341228 is about 863.7180060376.

The spelling of 644341228 in words is "six hundred forty-four million, three hundred forty-one thousand, two hundred twenty-eight".