1388438320 has 80 divisors (see below), whose sum is σ = 3365329248. Its totient is φ = 532224000.

The previous prime is 1388438291. The next prime is 1388438329. The reversal of 1388438320 is 238348831.

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 (40).

It is not an unprimeable number, because it can be changed into a prime (1388438329) by changing a digit.

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, 194820 + ... + 201820.

Almost surely, 2^1388438320 is an apocalyptic number.

1388438320 is a gapful number since it is divisible by the number (10) 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 1388438320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1682664624).

1388438320 is an abundant number, since it is smaller than the sum of its proper divisors (1976890928).

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

1388438320 is a wasteful number, since it uses less digits than its factorization.

1388438320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7118 (or 7112 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 40.

The square root of 1388438320 is about 37261.7541186670. The cubic root of 1388438320 is about 1115.6009201570.

The spelling of 1388438320 in words is "one billion, three hundred eighty-eight million, four hundred thirty-eight thousand, three hundred twenty".