640384 has 16 divisors (see below), whose sum is σ = 1276020. Its totient is φ = 320128.

The previous prime is 640369. The next prime is 640411. The reversal of 640384 is 483046.

It is a tau number, because it is divible by the number of its divisors (16).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2374 + ... + 2629.

2⁶⁴⁰³⁸⁴ is an apocalyptic number.

640384 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

640384 is a deficient number, since it is larger than the sum of its proper divisors (635636).

640384 is an equidigital number, since it uses as much as digits as its factorization.

640384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5017 (or 5005 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 640384 is about 800.2399640108. The cubic root of 640384 is about 86.1946196328.

It can be divided in two parts, 640 and 384, that added together give a 10-th power (1024 = 2¹⁰).

The spelling of 640384 in words is "six hundred forty thousand, three hundred eighty-four".