640641210 has 64 divisors (see below), whose sum is σ = 1709009280. Its totient is φ = 152372480.

The previous prime is 640641193. The next prime is 640641229. The reversal of 640641210 is 12146046.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 825 + ... + 35804.

It is an arithmetic number, because the mean of its divisors is an integer number (26703270).

Almost surely, 2^640641210 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640641210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (854504640).

640641210 is an abundant number, since it is smaller than the sum of its proper divisors (1068368070).

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

640641210 is a wasteful number, since it uses less digits than its factorization.

640641210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36703.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 640641210 is about 25310.8911340553. The cubic root of 640641210 is about 862.0615810069.

Adding to 640641210 its reverse (12146046), we get a palindrome (652787256).

The spelling of 640641210 in words is "six hundred forty million, six hundred forty-one thousand, two hundred ten".