91543813 has 2 divisors, whose sum is σ = 91543814. Its totient is φ = 91543812.

The previous prime is 91543801. The next prime is 91543849. The reversal of 91543813 is 31834519.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69856164 + 21687649 = 8358^2 + 4657^2 .

It is a cyclic number.

It is not a de Polignac number, because 91543813 - 2⁹ = 91543301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91543853) 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, 45771906 + 45771907.

It is an arithmetic number, because the mean of its divisors is an integer number (45771907).

Almost surely, 2^91543813 is an apocalyptic number.

It is an amenable number.

91543813 is a deficient number, since it is larger than the sum of its proper divisors (1).

91543813 is an equidigital number, since it uses as much as digits as its factorization.

91543813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 34.

The square root of 91543813 is about 9567.8531029693. The cubic root of 91543813 is about 450.6883506304.

The spelling of 91543813 in words is "ninety-one million, five hundred forty-three thousand, eight hundred thirteen".