91089065 has 4 divisors (see below), whose sum is σ = 109306884. Its totient is φ = 72871248.

The previous prime is 91089023. The next prime is 91089071. The reversal of 91089065 is 56098019.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56098019 = 6047 ⋅9277.

It can be written as a sum of positive squares in 2 ways, for example, as 55995289 + 35093776 = 7483^2 + 5924^2 .

It is a cyclic number.

It is not a de Polignac number, because 91089065 - 2⁶ = 91089001 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9108902 + ... + 9108911.

It is an arithmetic number, because the mean of its divisors is an integer number (27326721).

Almost surely, 2^91089065 is an apocalyptic number.

It is an amenable number.

91089065 is a deficient number, since it is larger than the sum of its proper divisors (18217819).

91089065 is a wasteful number, since it uses less digits than its factorization.

91089065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18217818.

The product of its (nonzero) digits is 19440, while the sum is 38.

The square root of 91089065 is about 9544.0591469249. The cubic root of 91089065 is about 449.9408399594.

The spelling of 91089065 in words is "ninety-one million, eighty-nine thousand, sixty-five".