391961903 has 2 divisors, whose sum is σ = 391961904. Its totient is φ = 391961902.

The previous prime is 391961891. The next prime is 391961917. The reversal of 391961903 is 309169193.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 391961903 - 2¹² = 391957807 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391961953) 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, 195980951 + 195980952.

It is an arithmetic number, because the mean of its divisors is an integer number (195980952).

Almost surely, 2^391961903 is an apocalyptic number.

391961903 is a deficient number, since it is larger than the sum of its proper divisors (1).

391961903 is an equidigital number, since it uses as much as digits as its factorization.

391961903 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 39366, while the sum is 41.

The square root of 391961903 is about 19798.0277553094. The cubic root of 391961903 is about 731.8374322961.

The spelling of 391961903 in words is "three hundred ninety-one million, nine hundred sixty-one thousand, nine hundred three".