640133 has 8 divisors (see below), whose sum is σ = 706776. Its totient is φ = 576000.

The previous prime is 640127. The next prime is 640139. The reversal of 640133 is 331046.

It is an interprime number because it is at equal distance from previous prime (640127) and next prime (640139).

It can be written as a sum of positive squares in 4 ways, for example, as 124609 + 515524 = 353^2 + 718^2 .

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 640133 - 2⁶ = 640069 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640139) 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, 68 + ... + 1133.

It is an arithmetic number, because the mean of its divisors is an integer number (88347).

2⁶⁴⁰¹³³ is an apocalyptic number.

It is an amenable number.

640133 is a deficient number, since it is larger than the sum of its proper divisors (66643).

640133 is a wasteful number, since it uses less digits than its factorization.

640133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1255.

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 640133 is about 800.0831206818. The cubic root of 640133 is about 86.1833567673.

Adding to 640133 its reverse (331046), we get a palindrome (971179).

The spelling of 640133 in words is "six hundred forty thousand, one hundred thirty-three".