640144384 has 88 divisors (see below), whose sum is σ = 1478556288. Its totient is φ = 273776640.

The previous prime is 640144381. The next prime is 640144391. The reversal of 640144384 is 483441046.

It is a tau number, because it is divible by the number of its divisors (88).

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640144381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 189817 + ... + 193159.

It is an arithmetic number, because the mean of its divisors is an integer number (16801776).

Almost surely, 2^640144384 is an apocalyptic number.

640144384 is a gapful number since it is divisible by the number (64) 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 640144384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (739278144).

640144384 is an abundant number, since it is smaller than the sum of its proper divisors (838411904).

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

640144384 is a wasteful number, since it uses less digits than its factorization.

640144384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3391 (or 3373 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 34.

The square root of 640144384 is about 25301.0747597805. The cubic root of 640144384 is about 861.8386765355.

The spelling of 640144384 in words is "six hundred forty million, one hundred forty-four thousand, three hundred eighty-four".