91249181 has 2 divisors, whose sum is σ = 91249182. Its totient is φ = 91249180.

The previous prime is 91249163. The next prime is 91249189. The reversal of 91249181 is 18194219.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90421081 + 828100 = 9509^2 + 910^2 .

It is a cyclic number.

It is not a de Polignac number, because 91249181 - 2¹⁴ = 91232797 is a prime.

It is a super-2 number, since 2×91249181² = 16652826066341522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91249189) 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, 45624590 + 45624591.

It is an arithmetic number, because the mean of its divisors is an integer number (45624591).

Almost surely, 2^91249181 is an apocalyptic number.

It is an amenable number.

91249181 is a deficient number, since it is larger than the sum of its proper divisors (1).

91249181 is an equidigital number, since it uses as much as digits as its factorization.

91249181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 35.

The square root of 91249181 is about 9552.4437187559. The cubic root of 91249181 is about 450.2043203840.

The spelling of 91249181 in words is "ninety-one million, two hundred forty-nine thousand, one hundred eighty-one".