438738640 has 20 divisors (see below), whose sum is σ = 1020067524. Its totient is φ = 175495424.

The previous prime is 438738631. The next prime is 438738649. The reversal of 438738640 is 46837834.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (438738631) and next prime (438738649).

It can be written as a sum of positive squares in 2 ways, for example, as 82737216 + 356001424 = 9096^2 + 18868^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (438738649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2742037 + ... + 2742196.

Almost surely, 2^438738640 is an apocalyptic number.

438738640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

438738640 is an abundant number, since it is smaller than the sum of its proper divisors (581328884).

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

438738640 is a wasteful number, since it uses less digits than its factorization.

438738640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5484246 (or 5484240 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 43.

The square root of 438738640 is about 20946.0888950658. The cubic root of 438738640 is about 759.8629946941.

The spelling of 438738640 in words is "four hundred thirty-eight million, seven hundred thirty-eight thousand, six hundred forty".