317428021 has 4 divisors (see below), whose sum is σ = 324810112. Its totient is φ = 310045932.

The previous prime is 317427973. The next prime is 317428043. The reversal of 317428021 is 120824713.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 317428021 - 2¹⁹ = 316903733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (317428081) 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, 3690981 + ... + 3691066.

It is an arithmetic number, because the mean of its divisors is an integer number (81202528).

Almost surely, 2^317428021 is an apocalyptic number.

It is an amenable number.

317428021 is a deficient number, since it is larger than the sum of its proper divisors (7382091).

317428021 is an equidigital number, since it uses as much as digits as its factorization.

317428021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7382090.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 317428021 is about 17816.5097872732. The cubic root of 317428021 is about 682.1529378119.

The spelling of 317428021 in words is "three hundred seventeen million, four hundred twenty-eight thousand, twenty-one".