91537081 has 2 divisors, whose sum is σ = 91537082. Its totient is φ = 91537080.

The previous prime is 91537049. The next prime is 91537087. The reversal of 91537081 is 18073519.

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., 89870400 + 1666681 = 9480^2 + 1291^2 .

It is an emirp because it is prime and its reverse (18073519) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91537081 - 2⁵ = 91537049 is a prime.

It is a super-2 number, since 2×91537081² = 16758074396001122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91537087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45768540 + 45768541.

It is an arithmetic number, because the mean of its divisors is an integer number (45768541).

Almost surely, 2^91537081 is an apocalyptic number.

It is an amenable number.

91537081 is a deficient number, since it is larger than the sum of its proper divisors (1).

91537081 is an equidigital number, since it uses as much as digits as its factorization.

91537081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 34.

The square root of 91537081 is about 9567.5012934413. The cubic root of 91537081 is about 450.6773027024.

The spelling of 91537081 in words is "ninety-one million, five hundred thirty-seven thousand, eighty-one".