861159240391 has 2 divisors, whose sum is σ = 861159240392. Its totient is φ = 861159240390.

The previous prime is 861159240373. The next prime is 861159240407. The reversal of 861159240391 is 193042951168.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 861159240391 - 2¹⁷ = 861159109319 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (861159240341) 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, 430579620195 + 430579620196.

It is an arithmetic number, because the mean of its divisors is an integer number (430579620196).

Almost surely, 2^861159240391 is an apocalyptic number.

861159240391 is a deficient number, since it is larger than the sum of its proper divisors (1).

861159240391 is an equidigital number, since it uses as much as digits as its factorization.

861159240391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 466560, while the sum is 49.

The spelling of 861159240391 in words is "eight hundred sixty-one billion, one hundred fifty-nine million, two hundred forty thousand, three hundred ninety-one".