91134721 has 2 divisors, whose sum is σ = 91134722. Its totient is φ = 91134720.

The previous prime is 91134707. The next prime is 91134727. The reversal of 91134721 is 12743119.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 85821696 + 5313025 = 9264^2 + 2305^2 .

It is an emirp because it is prime and its reverse (12743119) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91134721 - 2⁵ = 91134689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91134721.

It is not a weakly prime, because it can be changed into another prime (91134727) 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, 45567360 + 45567361.

It is an arithmetic number, because the mean of its divisors is an integer number (45567361).

Almost surely, 2^91134721 is an apocalyptic number.

It is an amenable number.

91134721 is a deficient number, since it is larger than the sum of its proper divisors (1).

91134721 is an equidigital number, since it uses as much as digits as its factorization.

91134721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 28.

The square root of 91134721 is about 9546.4507017006. The cubic root of 91134721 is about 450.0160010771.

The spelling of 91134721 in words is "ninety-one million, one hundred thirty-four thousand, seven hundred twenty-one".