640366 has 8 divisors (see below), whose sum is σ = 1002384. Its totient is φ = 306240.

The previous prime is 640363. The next prime is 640369. The reversal of 640366 is 663046.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (640363) and next prime (640369).

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

It is a super-2 number, since 2×640366² = 820137227912, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 640366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640363) by changing a digit.

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, 6915 + ... + 7006.

It is an arithmetic number, because the mean of its divisors is an integer number (125298).

2⁶⁴⁰³⁶⁶ is an apocalyptic number.

640366 is a deficient number, since it is larger than the sum of its proper divisors (362018).

640366 is a wasteful number, since it uses less digits than its factorization.

640366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13946.

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 640366 is about 800.2287173052. The cubic root of 640366 is about 86.1938120353.

The spelling of 640366 in words is "six hundred forty thousand, three hundred sixty-six".