391641269 has 2 divisors, whose sum is σ = 391641270. Its totient is φ = 391641268.

The previous prime is 391641253. The next prime is 391641323. The reversal of 391641269 is 962146193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 333500644 + 58140625 = 18262^2 + 7625^2 .

It is a cyclic number.

It is not a de Polignac number, because 391641269 - 2⁴ = 391641253 is a prime.

It is a super-2 number, since 2×391641269² = 306765767167860722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391641209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195820634 + 195820635.

It is an arithmetic number, because the mean of its divisors is an integer number (195820635).

Almost surely, 2^391641269 is an apocalyptic number.

It is an amenable number.

391641269 is a deficient number, since it is larger than the sum of its proper divisors (1).

391641269 is an equidigital number, since it uses as much as digits as its factorization.

391641269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69984, while the sum is 41.

The square root of 391641269 is about 19789.9284738475. The cubic root of 391641269 is about 731.6378244820.

The spelling of 391641269 in words is "three hundred ninety-one million, six hundred forty-one thousand, two hundred sixty-nine".