640504303643 has 8 divisors (see below), whose sum is σ = 648306021888. Its totient is φ = 632704604584.

The previous prime is 640504303601. The next prime is 640504303711. The reversal of 640504303643 is 346303405046.

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 640504303643 - 2²² = 640500109339 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640504303597 and 640504303606.

It is not an unprimeable number, because it can be changed into a prime (640504306643) 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, 138446 + ... + 1140252.

It is an arithmetic number, because the mean of its divisors is an integer number (81038252736).

Almost surely, 2^640504303643 is an apocalyptic number.

640504303643 is a deficient number, since it is larger than the sum of its proper divisors (7801718245).

640504303643 is a wasteful number, since it uses less digits than its factorization.

640504303643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1009593.

The product of its (nonzero) digits is 311040, while the sum is 38.

Adding to 640504303643 its reverse (346303405046), we get a palindrome (986807708689).

The spelling of 640504303643 in words is "six hundred forty billion, five hundred four million, three hundred three thousand, six hundred forty-three".