91806541 has 2 divisors, whose sum is σ = 91806542. Its totient is φ = 91806540.

The previous prime is 91806529. The next prime is 91806563. The reversal of 91806541 is 14560819.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91604041 + 202500 = 9571^2 + 450^2 .

It is a cyclic number.

It is not a de Polignac number, because 91806541 - 2¹⁹ = 91282253 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91806497 and 91806506.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91806521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45903270 + 45903271.

It is an arithmetic number, because the mean of its divisors is an integer number (45903271).

Almost surely, 2^91806541 is an apocalyptic number.

It is an amenable number.

91806541 is a deficient number, since it is larger than the sum of its proper divisors (1).

91806541 is an equidigital number, since it uses as much as digits as its factorization.

91806541 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 91806541 is about 9581.5729919466. The cubic root of 91806541 is about 451.1190928405.

The spelling of 91806541 in words is "ninety-one million, eight hundred six thousand, five hundred forty-one".