640240240 has 40 divisors (see below), whose sum is σ = 1490596560. Its totient is φ = 255745536.

The previous prime is 640240231. The next prime is 640240243. The reversal of 640240240 is 42042046.

It is a tau number, because it is divible by the number of its divisors (40).

640240240 is a modest number, since divided by 240240 gives 640 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640240243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57876 + ... + 68044.

It is an arithmetic number, because the mean of its divisors is an integer number (37264914).

Almost surely, 2^640240240 is an apocalyptic number.

It is an amenable number.

640240240 is an abundant number, since it is smaller than the sum of its proper divisors (850356320).

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

640240240 is a wasteful number, since it uses less digits than its factorization.

640240240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10969 (or 10963 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

The square root of 640240240 is about 25302.9689957523. The cubic root of 640240240 is about 861.8816919796.

Adding to 640240240 its reverse (42042046), we get a palindrome (682282286).

The spelling of 640240240 in words is "six hundred forty million, two hundred forty thousand, two hundred forty".