438406640 has 80 divisors (see below), whose sum is σ = 1169925120. Its totient is φ = 149664000.

The previous prime is 438406637. The next prime is 438406651. The reversal of 438406640 is 46604834.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 438406640.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139001 + ... + 142119.

It is an arithmetic number, because the mean of its divisors is an integer number (14624064).

Almost surely, 2^438406640 is an apocalyptic number.

438406640 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 438406640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (584962560).

438406640 is an abundant number, since it is smaller than the sum of its proper divisors (731518480).

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

438406640 is a wasteful number, since it uses less digits than its factorization.

438406640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3390 (or 3384 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 35.

The square root of 438406640 is about 20938.1622880328. The cubic root of 438406640 is about 759.6712798163.

The spelling of 438406640 in words is "four hundred thirty-eight million, four hundred six thousand, six hundred forty".