91863791 has 2 divisors, whose sum is σ = 91863792. Its totient is φ = 91863790.

The previous prime is 91863749. The next prime is 91863809. The reversal of 91863791 is 19736819.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91863791 - 2¹⁴ = 91847407 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91863721) 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, 45931895 + 45931896.

It is an arithmetic number, because the mean of its divisors is an integer number (45931896).

Almost surely, 2^91863791 is an apocalyptic number.

91863791 is a deficient number, since it is larger than the sum of its proper divisors (1).

91863791 is an equidigital number, since it uses as much as digits as its factorization.

91863791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 44.

The square root of 91863791 is about 9584.5600316342. The cubic root of 91863791 is about 451.2128450620.

The spelling of 91863791 in words is "ninety-one million, eight hundred sixty-three thousand, seven hundred ninety-one".