640198 has 8 divisors (see below), whose sum is σ = 1034208. Its totient is φ = 295464.

The previous prime is 640193. The next prime is 640219. The reversal of 640198 is 891046.

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

640198 is a modest number, since divided by 198 gives 64 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640193) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12286 + ... + 12337.

It is an arithmetic number, because the mean of its divisors is an integer number (129276).

2⁶⁴⁰¹⁹⁸ is an apocalyptic number.

640198 is a deficient number, since it is larger than the sum of its proper divisors (394010).

640198 is a wasteful number, since it uses less digits than its factorization.

640198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24638.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 640198 is about 800.1237404302. The cubic root of 640198 is about 86.1862737281.

It can be divided in two parts, 640 and 198, that added together give a palindrome (838).

The spelling of 640198 in words is "six hundred forty thousand, one hundred ninety-eight".