640246 has 8 divisors (see below), whose sum is σ = 966960. Its totient is φ = 317928.

The previous prime is 640231. The next prime is 640247. The reversal of 640246 is 642046.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640247) by changing a digit.

640246 is an untouchable number, because it is not equal to the sum of proper divisors of any 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, 706 + ... + 1333.

It is an arithmetic number, because the mean of its divisors is an integer number (120870).

2⁶⁴⁰²⁴⁶ is an apocalyptic number.

640246 is a deficient number, since it is larger than the sum of its proper divisors (326714).

640246 is a wasteful number, since it uses less digits than its factorization.

640246 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2198.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 640246 is about 800.1537352284. The cubic root of 640246 is about 86.1884276647.

It can be divided in two parts, 6402 and 46, that multiplied together give a palindrome (294492).

The spelling of 640246 in words is "six hundred forty thousand, two hundred forty-six".