91139161 has 2 divisors, whose sum is σ = 91139162. Its totient is φ = 91139160.

The previous prime is 91139149. The next prime is 91139201. The reversal of 91139161 is 16193119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89019225 + 2119936 = 9435^2 + 1456^2 .

It is an emirp because it is prime and its reverse (16193119) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91139161 - 2⁷ = 91139033 is a prime.

It is not a weakly prime, because it can be changed into another prime (91139131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45569580 + 45569581.

It is an arithmetic number, because the mean of its divisors is an integer number (45569581).

Almost surely, 2^91139161 is an apocalyptic number.

It is an amenable number.

91139161 is a deficient number, since it is larger than the sum of its proper divisors (1).

91139161 is an equidigital number, since it uses as much as digits as its factorization.

91139161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1458, while the sum is 31.

The square root of 91139161 is about 9546.6832460284. The cubic root of 91139161 is about 450.0233090807.

The spelling of 91139161 in words is "ninety-one million, one hundred thirty-nine thousand, one hundred sixty-one".