91124521 has 2 divisors, whose sum is σ = 91124522. Its totient is φ = 91124520.

The previous prime is 91124483. The next prime is 91124533. The reversal of 91124521 is 12542119.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90935296 + 189225 = 9536^2 + 435^2 .

It is a cyclic number.

It is not a de Polignac number, because 91124521 - 2⁷ = 91124393 is a prime.

It is not a weakly prime, because it can be changed into another prime (91124581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45562260 + 45562261.

It is an arithmetic number, because the mean of its divisors is an integer number (45562261).

Almost surely, 2^91124521 is an apocalyptic number.

It is an amenable number.

91124521 is a deficient number, since it is larger than the sum of its proper divisors (1).

91124521 is an equidigital number, since it uses as much as digits as its factorization.

91124521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 720, while the sum is 25.

The square root of 91124521 is about 9545.9164567893. The cubic root of 91124521 is about 449.9992115213. Note that the first 3 decimals are identical.

The spelling of 91124521 in words is "ninety-one million, one hundred twenty-four thousand, five hundred twenty-one".