428638 has 16 divisors (see below), whose sum is σ = 778464. Its totient is φ = 172800.

The previous prime is 428633. The next prime is 428639. The reversal of 428638 is 836824.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428633) by changing a digit.

428638 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 7 ways as a sum of consecutive naturals, for example, 663 + ... + 1138.

It is an arithmetic number, because the mean of its divisors is an integer number (48654).

2⁴²⁸⁶³⁸ is an apocalyptic number.

428638 is a deficient number, since it is larger than the sum of its proper divisors (349826).

428638 is a wasteful number, since it uses less digits than its factorization.

428638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1827.

The product of its digits is 9216, while the sum is 31.

The square root of 428638 is about 654.7045135021. The cubic root of 428638 is about 75.3986476831.

The spelling of 428638 in words is "four hundred twenty-eight thousand, six hundred thirty-eight".