640506120523 has 8 divisors (see below), whose sum is σ = 678255107040. Its totient is φ = 602765151360.

The previous prime is 640506120511. The next prime is 640506120559. The reversal of 640506120523 is 325021605046.

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 640506120523 - 2⁵ = 640506120491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640506120593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1839463 + ... + 2159776.

It is an arithmetic number, because the mean of its divisors is an integer number (84781888380).

Almost surely, 2^640506120523 is an apocalyptic number.

640506120523 is a deficient number, since it is larger than the sum of its proper divisors (37748986517).

640506120523 is a wasteful number, since it uses less digits than its factorization.

640506120523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4008677.

The product of its (nonzero) digits is 43200, while the sum is 34.

Adding to 640506120523 its reverse (325021605046), we get a palindrome (965527725569).

The spelling of 640506120523 in words is "six hundred forty billion, five hundred six million, one hundred twenty thousand, five hundred twenty-three".