91287261 has 12 divisors (see below), whose sum is σ = 142002588. Its totient is φ = 56176704.

The previous prime is 91287247. The next prime is 91287269. The reversal of 91287261 is 16278219.

It can be written as a sum of positive squares in 2 ways, for example, as 25190361 + 66096900 = 5019^2 + 8130^2 .

It is not a de Polignac number, because 91287261 - 2⁹ = 91286749 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91287269) 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 in 11 ways as a sum of consecutive naturals, for example, 390000 + ... + 390233.

It is an arithmetic number, because the mean of its divisors is an integer number (11833549).

Almost surely, 2^91287261 is an apocalyptic number.

It is an amenable number.

91287261 is a deficient number, since it is larger than the sum of its proper divisors (50715327).

91287261 is a wasteful number, since it uses less digits than its factorization.

91287261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 780252 (or 780249 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 91287261 is about 9554.4367180907. The cubic root of 91287261 is about 450.2669379186.

The spelling of 91287261 in words is "ninety-one million, two hundred eighty-seven thousand, two hundred sixty-one".