640831200 has 144 divisors (see below), whose sum is σ = 2102209200. Its totient is φ = 169553920.

The previous prime is 640831159. The next prime is 640831223. The reversal of 640831200 is 2138046.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 327826 + ... + 329774.

It is an arithmetic number, because the mean of its divisors is an integer number (14598675).

Almost surely, 2^640831200 is an apocalyptic number.

640831200 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 640831200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1051104600).

640831200 is an abundant number, since it is smaller than the sum of its proper divisors (1461378000).

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

640831200 is a wasteful number, since it uses less digits than its factorization.

640831200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2109 (or 2096 counting only the distinct ones).

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

The square root of 640831200 is about 25314.6439832758. The cubic root of 640831200 is about 862.1467908921.

Adding to 640831200 its reverse (2138046), we get a palindrome (642969246).

The spelling of 640831200 in words is "six hundred forty million, eight hundred thirty-one thousand, two hundred".