91819487 has 2 divisors, whose sum is σ = 91819488. Its totient is φ = 91819486.

The previous prime is 91819471. The next prime is 91819531. The reversal of 91819487 is 78491819.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91819487 - 2⁴ = 91819471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91819417) 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, 45909743 + 45909744.

It is an arithmetic number, because the mean of its divisors is an integer number (45909744).

Almost surely, 2^91819487 is an apocalyptic number.

91819487 is a deficient number, since it is larger than the sum of its proper divisors (1).

91819487 is an equidigital number, since it uses as much as digits as its factorization.

91819487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 47.

The square root of 91819487 is about 9582.2485357039. The cubic root of 91819487 is about 451.1402965341.

The spelling of 91819487 in words is "ninety-one million, eight hundred nineteen thousand, four hundred eighty-seven".