640922 has 8 divisors (see below), whose sum is σ = 975936. Its totient is φ = 315612.

The previous prime is 640919. The next prime is 640933. The reversal of 640922 is 229046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640922.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2258 + ... + 2525.

It is an arithmetic number, because the mean of its divisors is an integer number (121992).

2⁶⁴⁰⁹²² is an apocalyptic number.

640922 is a deficient number, since it is larger than the sum of its proper divisors (335014).

640922 is a wasteful number, since it uses less digits than its factorization.

640922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4852.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 640922 is about 800.5760426093. The cubic root of 640922 is about 86.2187508443.

Adding to 640922 its reverse (229046), we get a palindrome (869968).

The spelling of 640922 in words is "six hundred forty thousand, nine hundred twenty-two".