640508577845 has 6 divisors (see below), whose sum is σ = 768612440898. Its totient is φ = 512405430624.

The previous prime is 640508577833. The next prime is 640508577853. The reversal of 640508577845 is 548775805046.

It can be written as a sum of positive squares in 3 ways, for example, as 160302542884 + 480206034961 = 400378^2 + 692969^2 .

It is not a de Polignac number, because 640508577845 - 2²⁶ = 640441468981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1610609 + ... + 1968521.

It is an arithmetic number, because the mean of its divisors is an integer number (128102073483).

Almost surely, 2^640508577845 is an apocalyptic number.

It is an amenable number.

640508577845 is a deficient number, since it is larger than the sum of its proper divisors (128103863053).

640508577845 is an frugal number, since it uses more digits than its factorization.

640508577845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 715831 (or 357918 counting only the distinct ones).

The product of its (nonzero) digits is 37632000, while the sum is 59.

The spelling of 640508577845 in words is "six hundred forty billion, five hundred eight million, five hundred seventy-seven thousand, eight hundred forty-five".