640515130323 has 4 divisors (see below), whose sum is σ = 854020173768. Its totient is φ = 427010086880.

The previous prime is 640515130309. The next prime is 640515130327. The reversal of 640515130323 is 323031515046.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 640515130323 - 2⁶ = 640515130259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640515130327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106752521718 + ... + 106752521723.

It is an arithmetic number, because the mean of its divisors is an integer number (213505043442).

Almost surely, 2^640515130323 is an apocalyptic number.

640515130323 is a deficient number, since it is larger than the sum of its proper divisors (213505043445).

640515130323 is a wasteful number, since it uses less digits than its factorization.

640515130323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213505043444.

The product of its (nonzero) digits is 32400, while the sum is 33.

Adding to 640515130323 its reverse (323031515046), we get a palindrome (963546645369).

The spelling of 640515130323 in words is "six hundred forty billion, five hundred fifteen million, one hundred thirty thousand, three hundred twenty-three".