9665591 has 4 divisors (see below), whose sum is σ = 10409112. Its totient is φ = 8922072.

The previous prime is 9665587. The next prime is 9665609. The reversal of 9665591 is 1955669.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1955669 = 193 ⋅10133.

It is a cyclic number.

It is not a de Polignac number, because 9665591 - 2² = 9665587 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9665501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 371741 + ... + 371766.

It is an arithmetic number, because the mean of its divisors is an integer number (2602278).

Almost surely, 2^9665591 is an apocalyptic number.

9665591 is a deficient number, since it is larger than the sum of its proper divisors (743521).

9665591 is a wasteful number, since it uses less digits than its factorization.

9665591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743520.

The product of its digits is 72900, while the sum is 41.

The square root of 9665591 is about 3108.9533608596. The cubic root of 9665591 is about 213.0146492309.

The spelling of 9665591 in words is "nine million, six hundred sixty-five thousand, five hundred ninety-one".