423440 has 40 divisors (see below), whose sum is σ = 1011840. Its totient is φ = 164736.

The previous prime is 423439. The next prime is 423457. The reversal of 423440 is 44324.

It is a tau number, because it is divible by the number of its divisors (40).

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, 5321 + ... + 5399.

It is an arithmetic number, because the mean of its divisors is an integer number (25296).

2⁴²³⁴⁴⁰ is an apocalyptic number.

423440 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 423440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (505920).

423440 is an abundant number, since it is smaller than the sum of its proper divisors (588400).

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

423440 is a wasteful number, since it uses less digits than its factorization.

423440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159 (or 153 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 17.

The square root of 423440 is about 650.7226751851. The cubic root of 423440 is about 75.0926262986.

Adding to 423440 its reverse (44324), we get a palindrome (467764).

The spelling of 423440 in words is "four hundred twenty-three thousand, four hundred forty", and thus it is an iban number.