91534561 has 2 divisors, whose sum is σ = 91534562. Its totient is φ = 91534560.

The previous prime is 91534519. The next prime is 91534567. The reversal of 91534561 is 16543519.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67963536 + 23571025 = 8244^2 + 4855^2 .

It is a cyclic number.

It is not a de Polignac number, because 91534561 - 2⁹ = 91534049 is a prime.

It is not a weakly prime, because it can be changed into another prime (91534567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45767280 + 45767281.

It is an arithmetic number, because the mean of its divisors is an integer number (45767281).

Almost surely, 2^91534561 is an apocalyptic number.

It is an amenable number.

91534561 is a deficient number, since it is larger than the sum of its proper divisors (1).

91534561 is an equidigital number, since it uses as much as digits as its factorization.

91534561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16200, while the sum is 34.

The square root of 91534561 is about 9567.3695967073. The cubic root of 91534561 is about 450.6731669751.

The spelling of 91534561 in words is "ninety-one million, five hundred thirty-four thousand, five hundred sixty-one".