438640 has 20 divisors (see below), whose sum is σ = 1020024. Its totient is φ = 175424.

The previous prime is 438637. The next prime is 438661. The reversal of 438640 is 46834.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2662 + ... + 2821.

2⁴³⁸⁶⁴⁰ is an apocalyptic number.

438640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

438640 is an abundant number, since it is smaller than the sum of its proper divisors (581384).

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

438640 is a wasteful number, since it uses less digits than its factorization.

438640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5496 (or 5490 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 438640 is about 662.2990261204. The cubic root of 438640 is about 75.9806044689.

The spelling of 438640 in words is "four hundred thirty-eight thousand, six hundred forty".