640024 has 32 divisors (see below), whose sum is σ = 1497600. Its totient is φ = 249120.

The previous prime is 640019. The next prime is 640027. The reversal of 640024 is 420046.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640027) by changing a digit.

640024 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 in 7 ways as a sum of consecutive naturals, for example, 97 + ... + 1135.

It is an arithmetic number, because the mean of its divisors is an integer number (46800).

640024 is a Friedman number, since it can be written as 4*(6+(20+0)^4), using all its digits and the basic arithmetic operations.

2⁶⁴⁰⁰²⁴ 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 640024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (748800).

640024 is an abundant number, since it is smaller than the sum of its proper divisors (857576).

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

640024 is a wasteful number, since it uses less digits than its factorization.

640024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063 (or 1059 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 640024 is about 800.0149998594. The cubic root of 640024 is about 86.1784648052.

The spelling of 640024 in words is "six hundred forty thousand, twenty-four".