640033 has 4 divisors (see below), whose sum is σ = 677700. Its totient is φ = 602368.

The previous prime is 640027. The next prime is 640039. The reversal of 640033 is 330046.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (640027) and next prime (640039).

It can be written as a sum of positive squares in 2 ways, for example, as 565504 + 74529 = 752^2 + 273^2 .

It is a cyclic number.

It is not a de Polignac number, because 640033 - 2¹⁷ = 508961 is a prime.

It is a Duffinian number.

640033 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 639989 and 640016.

It is not an unprimeable number, because it can be changed into a prime (640039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18808 + ... + 18841.

It is an arithmetic number, because the mean of its divisors is an integer number (169425).

2⁶⁴⁰⁰³³ is an apocalyptic number.

It is an amenable number.

640033 is a deficient number, since it is larger than the sum of its proper divisors (37667).

640033 is a wasteful number, since it uses less digits than its factorization.

640033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37666.

The product of its (nonzero) digits is 216, while the sum is 16.

The square root of 640033 is about 800.0206247341. The cubic root of 640033 is about 86.1788687497.

Adding to 640033 its reverse (330046), we get a palindrome (970079).

The spelling of 640033 in words is "six hundred forty thousand, thirty-three".