640934 has 16 divisors (see below), whose sum is σ = 1163808. Its totient is φ = 258432.

The previous prime is 640933. The next prime is 640943. The reversal of 640934 is 439046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1109 + ... + 1584.

It is an arithmetic number, because the mean of its divisors is an integer number (72738).

2⁶⁴⁰⁹³⁴ is an apocalyptic number.

640934 is a deficient number, since it is larger than the sum of its proper divisors (522874).

640934 is a wasteful number, since it uses less digits than its factorization.

640934 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2719.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 640934 is about 800.5835371777. The cubic root of 640934 is about 86.2192889330.

The spelling of 640934 in words is "six hundred forty thousand, nine hundred thirty-four".