1644878228 has 48 divisors (see below), whose sum is σ = 3453542400. Its totient is φ = 670623840.

The previous prime is 1644878159. The next prime is 1644878243. The reversal of 1644878228 is 8228784461.

It is a congruent number.

It is an unprimeable number.

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, 35153 + ... + 67271.

It is an arithmetic number, because the mean of its divisors is an integer number (71948800).

Almost surely, 2^1644878228 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1644878228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1726771200).

1644878228 is an abundant number, since it is smaller than the sum of its proper divisors (1808664172).

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

1644878228 is a wasteful number, since it uses less digits than its factorization.

1644878228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32220 (or 32218 counting only the distinct ones).

The product of its digits is 1376256, while the sum is 50.

The square root of 1644878228 is about 40557.0983676101. The cubic root of 1644878228 is about 1180.4418119586.

The spelling of 1644878228 in words is "one billion, six hundred forty-four million, eight hundred seventy-eight thousand, two hundred twenty-eight".