640433 has 8 divisors (see below), whose sum is σ = 693120. Its totient is φ = 589680.

The previous prime is 640421. The next prime is 640457. The reversal of 640433 is 334046.

It is a happy number.

640433 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 640433 - 2⁶ = 640369 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640463) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 248 + ... + 1158.

It is an arithmetic number, because the mean of its divisors is an integer number (86640).

2⁶⁴⁰⁴³³ is an apocalyptic number.

It is an amenable number.

640433 is a deficient number, since it is larger than the sum of its proper divisors (52687).

640433 is a wasteful number, since it uses less digits than its factorization.

640433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 967.

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 640433 is about 800.2705792418. The cubic root of 640433 is about 86.1968180162.

Adding to 640433 its reverse (334046), we get a palindrome (974479).

It can be divided in two parts, 64043 and 3, that added together give a palindrome (64046).

The spelling of 640433 in words is "six hundred forty thousand, four hundred thirty-three".