640815319727 has 8 divisors (see below), whose sum is σ = 700141818960. Its totient is φ = 581667247360.

The previous prime is 640815319643. The next prime is 640815319757. The reversal of 640815319727 is 727913518046.

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

It is a cyclic number.

It is not a de Polignac number, because 640815319727 - 2⁸ = 640815319471 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640815319757) 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, 44599202 + ... + 44613567.

It is an arithmetic number, because the mean of its divisors is an integer number (87517727370).

It is a 1-persistent number, because it is pandigital, but 2⋅640815319727 = 1281630639454 is not.

Almost surely, 2^640815319727 is an apocalyptic number.

640815319727 is a deficient number, since it is larger than the sum of its proper divisors (59326499233).

640815319727 is a wasteful number, since it uses less digits than its factorization.

640815319727 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89213433.

The product of its (nonzero) digits is 2540160, while the sum is 53.

The spelling of 640815319727 in words is "six hundred forty billion, eight hundred fifteen million, three hundred nineteen thousand, seven hundred twenty-seven".