640317273 has 8 divisors (see below), whose sum is σ = 862558368. Its totient is φ = 422477184.

The previous prime is 640317259. The next prime is 640317277. The reversal of 640317273 is 372713046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 640317273 - 2⁸ = 640317017 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640317277) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1099911 + ... + 1100492.

It is an arithmetic number, because the mean of its divisors is an integer number (107819796).

Almost surely, 2^640317273 is an apocalyptic number.

It is an amenable number.

640317273 is a deficient number, since it is larger than the sum of its proper divisors (222241095).

640317273 is a wasteful number, since it uses less digits than its factorization.

640317273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2200503.

The product of its (nonzero) digits is 21168, while the sum is 33.

The square root of 640317273 is about 25304.4911626375. The cubic root of 640317273 is about 861.9162574785.

The spelling of 640317273 in words is "six hundred forty million, three hundred seventeen thousand, two hundred seventy-three".