91186661 has 2 divisors, whose sum is σ = 91186662. Its totient is φ = 91186660.

The previous prime is 91186639. The next prime is 91186687. The reversal of 91186661 is 16668119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90136036 + 1050625 = 9494^2 + 1025^2 .

It is a cyclic number.

It is not a de Polignac number, because 91186661 - 2⁶ = 91186597 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91186631) 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, 45593330 + 45593331.

It is an arithmetic number, because the mean of its divisors is an integer number (45593331).

Almost surely, 2^91186661 is an apocalyptic number.

It is an amenable number.

91186661 is a deficient number, since it is larger than the sum of its proper divisors (1).

91186661 is an equidigital number, since it uses as much as digits as its factorization.

91186661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 38.

The square root of 91186661 is about 9549.1706969768. The cubic root of 91186661 is about 450.1014767034.

The spelling of 91186661 in words is "ninety-one million, one hundred eighty-six thousand, six hundred sixty-one".