91288065 has 64 divisors (see below), whose sum is σ = 172477440. Its totient is φ = 40746240.

The previous prime is 91288049. The next prime is 91288073. The reversal of 91288065 is 56088219.

It is not a de Polignac number, because 91288065 - 2⁴ = 91288049 is a prime.

It is a super-2 number, since 2×91288065² = 16667021622888450, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 115602 + ... + 116388.

It is an arithmetic number, because the mean of its divisors is an integer number (2694960).

Almost surely, 2^91288065 is an apocalyptic number.

91288065 is a gapful number since it is divisible by the number (95) formed by its first and last digit.

It is an amenable number.

91288065 is a deficient number, since it is larger than the sum of its proper divisors (81189375).

91288065 is a wasteful number, since it uses less digits than its factorization.

91288065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862.

The product of its (nonzero) digits is 34560, while the sum is 39.

The square root of 91288065 is about 9554.4787926919. The cubic root of 91288065 is about 450.2682598028.

The spelling of 91288065 in words is "ninety-one million, two hundred eighty-eight thousand, sixty-five".