91109687 has 2 divisors, whose sum is σ = 91109688. Its totient is φ = 91109686.

The previous prime is 91109657. The next prime is 91109717. The reversal of 91109687 is 78690119.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (91109657) and next prime (91109717).

It is an emirp because it is prime and its reverse (78690119) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91109687 - 2¹⁰ = 91108663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91109657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45554843 + 45554844.

It is an arithmetic number, because the mean of its divisors is an integer number (45554844).

Almost surely, 2^91109687 is an apocalyptic number.

91109687 is a deficient number, since it is larger than the sum of its proper divisors (1).

91109687 is an equidigital number, since it uses as much as digits as its factorization.

91109687 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 91109687 is about 9545.1394437169. The cubic root of 91109687 is about 449.9747920036.

The spelling of 91109687 in words is "ninety-one million, one hundred nine thousand, six hundred eighty-seven".