640383 has 4 divisors (see below), whose sum is σ = 853848. Its totient is φ = 426920.

The previous prime is 640369. The next prime is 640411. The reversal of 640383 is 383046.

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

It is a cyclic number.

It is not a de Polignac number, because 640383 - 2⁸ = 640127 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106728 + ... + 106733.

It is an arithmetic number, because the mean of its divisors is an integer number (213462).

2⁶⁴⁰³⁸³ is an apocalyptic number.

640383 is a deficient number, since it is larger than the sum of its proper divisors (213465).

640383 is a wasteful number, since it uses less digits than its factorization.

640383 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213464.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 640383 is about 800.2393391980. The cubic root of 640383 is about 86.1945747667.

The spelling of 640383 in words is "six hundred forty thousand, three hundred eighty-three".