640306605 has 32 divisors (see below), whose sum is σ = 1044062208. Its totient is φ = 335016000.

The previous prime is 640306577. The next prime is 640306633. The reversal of 640306605 is 506603046.

640306605 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (640306577) and next prime (640306633).

It is not a de Polignac number, because 640306605 - 2¹¹ = 640304557 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 271180 + ... + 273530.

It is an arithmetic number, because the mean of its divisors is an integer number (32626944).

Almost surely, 2^640306605 is an apocalyptic number.

It is an amenable number.

640306605 is a deficient number, since it is larger than the sum of its proper divisors (403755603).

640306605 is a wasteful number, since it uses less digits than its factorization.

640306605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2697.

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 640306605 is about 25304.2803691391. The cubic root of 640306605 is about 861.9114708026.

The spelling of 640306605 in words is "six hundred forty million, three hundred six thousand, six hundred five".