388640 has 48 divisors (see below), whose sum is σ = 1052352. Its totient is φ = 132864.

The previous prime is 388621. The next prime is 388651. The reversal of 388640 is 46883.

It is an unprimeable number.

388640 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 947 + ... + 1293.

It is an arithmetic number, because the mean of its divisors is an integer number (21924).

2³⁸⁸⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 388640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (526176).

388640 is an abundant number, since it is smaller than the sum of its proper divisors (663712).

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

388640 is a wasteful number, since it uses less digits than its factorization.

388640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369 (or 361 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 388640 is about 623.4099774627. The cubic root of 388640 is about 72.9764107181.

The spelling of 388640 in words is "three hundred eighty-eight thousand, six hundred forty".