640815319767 has 64 divisors (see below), whose sum is σ = 1031726039040. Its totient is φ = 345609763200.

The previous prime is 640815319759. The next prime is 640815319769. The reversal of 640815319767 is 767913518046.

It is a happy number.

It is not a de Polignac number, because 640815319767 - 2³ = 640815319759 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640815319769) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 178946917 + ... + 178950497.

It is an arithmetic number, because the mean of its divisors is an integer number (16120719360).

Almost surely, 2^640815319767 is an apocalyptic number.

640815319767 is a deficient number, since it is larger than the sum of its proper divisors (390910719273).

640815319767 is a wasteful number, since it uses less digits than its factorization.

640815319767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5164.

The product of its (nonzero) digits is 7620480, while the sum is 57.

The spelling of 640815319767 in words is "six hundred forty billion, eight hundred fifteen million, three hundred nineteen thousand, seven hundred sixty-seven".