640715365 has 8 divisors (see below), whose sum is σ = 769033368. Its totient is φ = 512455680.

The previous prime is 640715333. The next prime is 640715389. The reversal of 640715365 is 563517046.

It can be written as a sum of positive squares in 4 ways, for example, as 224310529 + 416404836 = 14977^2 + 20406^2 .

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

It is not a de Polignac number, because 640715365 - 2⁵ = 640715333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15085 + ... + 38845.

It is an arithmetic number, because the mean of its divisors is an integer number (96129171).

Almost surely, 2^640715365 is an apocalyptic number.

It is an amenable number.

640715365 is a deficient number, since it is larger than the sum of its proper divisors (128318003).

640715365 is a wasteful number, since it uses less digits than its factorization.

640715365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29159.

The product of its (nonzero) digits is 75600, while the sum is 37.

The square root of 640715365 is about 25312.3559748989. The cubic root of 640715365 is about 862.0948412828.

The spelling of 640715365 in words is "six hundred forty million, seven hundred fifteen thousand, three hundred sixty-five".