391039679 has 2 divisors, whose sum is σ = 391039680. Its totient is φ = 391039678.

The previous prime is 391039667. The next prime is 391039687. The reversal of 391039679 is 976930193.

It is a strong prime.

It is an emirp because it is prime and its reverse (976930193) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 391039679 - 2¹² = 391035583 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 (391039619) 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, 195519839 + 195519840.

It is an arithmetic number, because the mean of its divisors is an integer number (195519840).

Almost surely, 2^391039679 is an apocalyptic number.

391039679 is a deficient number, since it is larger than the sum of its proper divisors (1).

391039679 is an equidigital number, since it uses as much as digits as its factorization.

391039679 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 275562, while the sum is 47.

The square root of 391039679 is about 19774.7232344728. The cubic root of 391039679 is about 731.2630158737.

The spelling of 391039679 in words is "three hundred ninety-one million, thirty-nine thousand, six hundred seventy-nine".