91281247 has 2 divisors, whose sum is σ = 91281248. Its totient is φ = 91281246.

The previous prime is 91281233. The next prime is 91281271. The reversal of 91281247 is 74218219.

It is a weak prime.

It is an emirp because it is prime and its reverse (74218219) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91281247 - 2⁷ = 91281119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91284247) 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, 45640623 + 45640624.

It is an arithmetic number, because the mean of its divisors is an integer number (45640624).

Almost surely, 2^91281247 is an apocalyptic number.

91281247 is a deficient number, since it is larger than the sum of its proper divisors (1).

91281247 is an equidigital number, since it uses as much as digits as its factorization.

91281247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 34.

The square root of 91281247 is about 9554.1219900104. The cubic root of 91281247 is about 450.2570498474.

The spelling of 91281247 in words is "ninety-one million, two hundred eighty-one thousand, two hundred forty-seven".