640322 has 16 divisors (see below), whose sum is σ = 1046520. Its totient is φ = 292608.

The previous prime is 640307. The next prime is 640333. The reversal of 640322 is 223046.

It can be written as a sum of positive squares in 4 ways, for example, as 625681 + 14641 = 791^2 + 121^2 .

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 640322.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640322.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1004 + ... + 1512.

2⁶⁴⁰³²² is an apocalyptic number.

640322 is a deficient number, since it is larger than the sum of its proper divisors (406198).

640322 is a wasteful number, since it uses less digits than its factorization.

640322 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 640322 is about 800.2012246929. The cubic root of 640322 is about 86.1918378442.

Adding to 640322 its reverse (223046), we get a palindrome (863368).

The spelling of 640322 in words is "six hundred forty thousand, three hundred twenty-two".