391317853 has 2 divisors, whose sum is σ = 391317854. Its totient is φ = 391317852.

The previous prime is 391317841. The next prime is 391317919. The reversal of 391317853 is 358713193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 311804964 + 79512889 = 17658^2 + 8917^2 .

It is a cyclic number.

It is not a de Polignac number, because 391317853 - 2²¹ = 389220701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391317803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195658926 + 195658927.

It is an arithmetic number, because the mean of its divisors is an integer number (195658927).

Almost surely, 2^391317853 is an apocalyptic number.

It is an amenable number.

391317853 is a deficient number, since it is larger than the sum of its proper divisors (1).

391317853 is an equidigital number, since it uses as much as digits as its factorization.

391317853 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 40.

The square root of 391317853 is about 19781.7555591004. The cubic root of 391317853 is about 731.4363743613.

The spelling of 391317853 in words is "three hundred ninety-one million, three hundred seventeen thousand, eight hundred fifty-three".