640281333 has 16 divisors (see below), whose sum is σ = 867104000. Its totient is φ = 420189120.

The previous prime is 640281331. The next prime is 640281359. The reversal of 640281333 is 333182046.

It is not a de Polignac number, because 640281333 - 2¹ = 640281331 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 640281333.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640281331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78843 + ... + 86583.

It is an arithmetic number, because the mean of its divisors is an integer number (54194000).

Almost surely, 2^640281333 is an apocalyptic number.

It is an amenable number.

640281333 is a deficient number, since it is larger than the sum of its proper divisors (226822667).

640281333 is a wasteful number, since it uses less digits than its factorization.

640281333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8172.

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 640281333 is about 25303.7810020558. The cubic root of 640281333 is about 861.9001311761.

The spelling of 640281333 in words is "six hundred forty million, two hundred eighty-one thousand, three hundred thirty-three".