640315305 has 48 divisors (see below), whose sum is σ = 1270214400. Its totient is φ = 292305024.

The previous prime is 640315289. The next prime is 640315321. The reversal of 640315305 is 503513046.

640315305 is a `hidden beast` number, since 6 + 40 + 315 + 305 = 666.

It is an interprime number because it is at equal distance from previous prime (640315289) and next prime (640315321).

It is not a de Polignac number, because 640315305 - 2⁴ = 640315289 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 439959 + ... + 441411.

It is an arithmetic number, because the mean of its divisors is an integer number (26462800).

Almost surely, 2^640315305 is an apocalyptic number.

It is an amenable number.

640315305 is a deficient number, since it is larger than the sum of its proper divisors (629899095).

640315305 is a wasteful number, since it uses less digits than its factorization.

640315305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2870 (or 2867 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 27.

The square root of 640315305 is about 25304.4522762300. The cubic root of 640315305 is about 861.9153744511.

The spelling of 640315305 in words is "six hundred forty million, three hundred fifteen thousand, three hundred five".