640652 has 6 divisors (see below), whose sum is σ = 1121148. Its totient is φ = 320324.

The previous prime is 640649. The next prime is 640663. The reversal of 640652 is 256046.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640652.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80078 + ... + 80085.

It is an arithmetic number, because the mean of its divisors is an integer number (186858).

2⁶⁴⁰⁶⁵² is an apocalyptic number.

It is an amenable number.

640652 is a deficient number, since it is larger than the sum of its proper divisors (480496).

640652 is a wasteful number, since it uses less digits than its factorization.

640652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160167 (or 160165 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 640652 is about 800.4073962677. The cubic root of 640652 is about 86.2066420737.

Adding to 640652 its reverse (256046), we get a palindrome (896698).

The spelling of 640652 in words is "six hundred forty thousand, six hundred fifty-two".