317740721 has 4 divisors (see below), whose sum is σ = 317876772. Its totient is φ = 317604672.

The previous prime is 317740711. The next prime is 317740739. The reversal of 317740721 is 127047713.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127047713 = 13 ⋅9772901.

It can be written as a sum of positive squares in 2 ways, for example, as 88642225 + 229098496 = 9415^2 + 15136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-317740721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (317740711) 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, 64460 + ... + 69213.

It is an arithmetic number, because the mean of its divisors is an integer number (79469193).

Almost surely, 2^317740721 is an apocalyptic number.

It is an amenable number.

317740721 is a deficient number, since it is larger than the sum of its proper divisors (136051).

317740721 is a wasteful number, since it uses less digits than its factorization.

317740721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136050.

The product of its (nonzero) digits is 8232, while the sum is 32.

The square root of 317740721 is about 17825.2831955063. The cubic root of 317740721 is about 682.3768617714.

The spelling of 317740721 in words is "three hundred seventeen million, seven hundred forty thousand, seven hundred twenty-one".