428644 has 12 divisors (see below), whose sum is σ = 758268. Its totient is φ = 212000.

The previous prime is 428639. The next prime is 428657. The reversal of 428644 is 446824.

It can be written as a sum of positive squares in 2 ways, for example, as 360000 + 68644 = 600^2 + 262^2 .

It is an unprimeable number.

428644 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 3 ways as a sum of consecutive naturals, for example, 127 + ... + 934.

It is an arithmetic number, because the mean of its divisors is an integer number (63189).

2⁴²⁸⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

428644 is a deficient number, since it is larger than the sum of its proper divisors (329624).

428644 is a wasteful number, since it uses less digits than its factorization.

428644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1166 (or 1164 counting only the distinct ones).

The product of its digits is 6144, while the sum is 28.

The square root of 428644 is about 654.7090957059. The cubic root of 428644 is about 75.3989994872.

Subtracting from 428644 its product of digits (6144), we obtain a square (422500 = 650²).

The spelling of 428644 in words is "four hundred twenty-eight thousand, six hundred forty-four".