91804543687 has 2 divisors, whose sum is σ = 91804543688. Its totient is φ = 91804543686.

The previous prime is 91804543667. The next prime is 91804543711. The reversal of 91804543687 is 78634540819.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91804543687 - 2¹⁹ = 91804019399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91804543627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45902271843 + 45902271844.

It is an arithmetic number, because the mean of its divisors is an integer number (45902271844).

Almost surely, 2^91804543687 is an apocalyptic number.

91804543687 is a deficient number, since it is larger than the sum of its proper divisors (1).

91804543687 is an equidigital number, since it uses as much as digits as its factorization.

91804543687 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5806080, while the sum is 55.

The spelling of 91804543687 in words is "ninety-one billion, eight hundred four million, five hundred forty-three thousand, six hundred eighty-seven".