317749921 has 4 divisors (see below), whose sum is σ = 322225344. Its totient is φ = 313274500.

The previous prime is 317749903. The next prime is 317749937. The reversal of 317749921 is 129947713.

It is a happy number.

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 317749921 - 2⁵ = 317749889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (317749961) 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, 2237605 + ... + 2237746.

It is an arithmetic number, because the mean of its divisors is an integer number (80556336).

Almost surely, 2^317749921 is an apocalyptic number.

It is an amenable number.

317749921 is a deficient number, since it is larger than the sum of its proper divisors (4475423).

317749921 is an equidigital number, since it uses as much as digits as its factorization.

317749921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4475422.

The product of its digits is 95256, while the sum is 43.

The square root of 317749921 is about 17825.5412540545. The cubic root of 317749921 is about 682.3834476512.

The spelling of 317749921 in words is "three hundred seventeen million, seven hundred forty-nine thousand, nine hundred twenty-one".