391081013 has 2 divisors, whose sum is σ = 391081014. Its totient is φ = 391081012.

The previous prime is 391081007. The next prime is 391081021. The reversal of 391081013 is 310180193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 297804049 + 93276964 = 17257^2 + 9658^2 .

It is a cyclic number.

It is not a de Polignac number, because 391081013 - 2⁸ = 391080757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391081003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195540506 + 195540507.

It is an arithmetic number, because the mean of its divisors is an integer number (195540507).

Almost surely, 2^391081013 is an apocalyptic number.

It is an amenable number.

391081013 is a deficient number, since it is larger than the sum of its proper divisors (1).

391081013 is an equidigital number, since it uses as much as digits as its factorization.

391081013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 391081013 is about 19775.7683289424. The cubic root of 391081013 is about 731.2887804889.

The spelling of 391081013 in words is "three hundred ninety-one million, eighty-one thousand, thirteen".