640964 has 12 divisors (see below), whose sum is σ = 1170624. Its totient is φ = 306504.

The previous prime is 640963. The next prime is 640967. The reversal of 640964 is 469046.

640964 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (640963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3392 + ... + 3575.

It is an arithmetic number, because the mean of its divisors is an integer number (97552).

2⁶⁴⁰⁹⁶⁴ is an apocalyptic number.

It is an amenable number.

640964 is a deficient number, since it is larger than the sum of its proper divisors (529660).

640964 is a wasteful number, since it uses less digits than its factorization.

640964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6994 (or 6992 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 640964 is about 800.6022732918. The cubic root of 640964 is about 86.2206341252.

The spelling of 640964 in words is "six hundred forty thousand, nine hundred sixty-four".