91281761 has 2 divisors, whose sum is σ = 91281762. Its totient is φ = 91281760.

The previous prime is 91281737. The next prime is 91281767. The reversal of 91281761 is 16718219.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89889361 + 1392400 = 9481^2 + 1180^2 .

It is a cyclic number.

It is not a de Polignac number, because 91281761 - 2²² = 87087457 is a prime.

It is a super-2 number, since 2×91281761² = 16664719782522242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91281767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45640880 + 45640881.

It is an arithmetic number, because the mean of its divisors is an integer number (45640881).

Almost surely, 2^91281761 is an apocalyptic number.

It is an amenable number.

91281761 is a deficient number, since it is larger than the sum of its proper divisors (1).

91281761 is an equidigital number, since it uses as much as digits as its factorization.

91281761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 35.

The square root of 91281761 is about 9554.1488893569. The cubic root of 91281761 is about 450.2578949705.

The spelling of 91281761 in words is "ninety-one million, two hundred eighty-one thousand, seven hundred sixty-one".