640220268 has 24 divisors (see below), whose sum is σ = 1497424320. Its totient is φ = 212895760.

The previous prime is 640220267. The next prime is 640220281. The reversal of 640220268 is 862022046.

640220268 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (640220261) 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, 58638 + ... + 68693.

It is an arithmetic number, because the mean of its divisors is an integer number (62392680).

Almost surely, 2^640220268 is an apocalyptic number.

It is an amenable number.

640220268 is an abundant number, since it is smaller than the sum of its proper divisors (857204052).

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

640220268 is a wasteful number, since it uses less digits than its factorization.

640220268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127757 (or 127755 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 640220268 is about 25302.5743354308. The cubic root of 640220268 is about 861.8727298854.

The spelling of 640220268 in words is "six hundred forty million, two hundred twenty thousand, two hundred sixty-eight".