644283228 has 24 divisors (see below), whose sum is σ = 1507669632. Its totient is φ = 214140784.

The previous prime is 644283197. The next prime is 644283239. The reversal of 644283228 is 822382446.

It is a super-3 number, since 3×644283228³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73200 + ... + 81527.

It is an arithmetic number, because the mean of its divisors is an integer number (62819568).

Almost surely, 2^644283228 is an apocalyptic number.

It is an amenable number.

644283228 is an abundant number, since it is smaller than the sum of its proper divisors (863386404).

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

644283228 is a wasteful number, since it uses less digits than its factorization.

644283228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155081 (or 155079 counting only the distinct ones).

The product of its digits is 147456, while the sum is 39.

The square root of 644283228 is about 25382.7348408323. The cubic root of 644283228 is about 863.6920895690.

The spelling of 644283228 in words is "six hundred forty-four million, two hundred eighty-three thousand, two hundred twenty-eight".