317785844521 has 4 divisors (see below), whose sum is σ = 317809543252. Its totient is φ = 317762145792.

The previous prime is 317785844513. The next prime is 317785844539. The reversal of 317785844521 is 125448587713.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 125448587713 = 17 ⋅7379328689.

It can be written as a sum of positive squares in 2 ways, for example, as 239531936400 + 78253908121 = 489420^2 + 279739^2 .

It is a cyclic number.

It is not a de Polignac number, because 317785844521 - 2³ = 317785844513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (317785844561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11829240 + ... + 11856073.

It is an arithmetic number, because the mean of its divisors is an integer number (79452385813).

Almost surely, 2^317785844521 is an apocalyptic number.

It is an amenable number.

317785844521 is a deficient number, since it is larger than the sum of its proper divisors (23698731).

317785844521 is a wasteful number, since it uses less digits than its factorization.

317785844521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23698730.

The product of its digits is 7526400, while the sum is 55.

The spelling of 317785844521 in words is "three hundred seventeen billion, seven hundred eighty-five million, eight hundred forty-four thousand, five hundred twenty-one".