640650240 has 132 divisors (see below), whose sum is σ = 2219996064. Its totient is φ = 170827776.

The previous prime is 640650239. The next prime is 640650251. The reversal of 640650240 is 42056046.

It is a happy number.

640650240 is a `hidden beast` number, since 6 + 4 + 0 + 650 + 2 + 4 + 0 = 666.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 39129 + ... + 53031.

It is an arithmetic number, because the mean of its divisors is an integer number (16818152).

Almost surely, 2^640650240 is an apocalyptic number.

640650240 is a gapful number since it is divisible by the number (60) 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 640650240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1109998032).

640650240 is an abundant number, since it is smaller than the sum of its proper divisors (1579345824).

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

640650240 is a wasteful number, since it uses less digits than its factorization.

640650240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13934 (or 13913 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 640650240 is about 25311.0695151351. The cubic root of 640650240 is about 862.0656313133.

The spelling of 640650240 in words is "six hundred forty million, six hundred fifty thousand, two hundred forty".