9665581 has 4 divisors (see below), whose sum is σ = 9719164. Its totient is φ = 9612000.

The previous prime is 9665567. The next prime is 9665587. The reversal of 9665581 is 1855669.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 695556 + 8970025 = 834^2 + 2995^2 .

It is a cyclic number.

It is not a de Polignac number, because 9665581 - 2⁹ = 9665069 is a prime.

It is a super-2 number, since 2×9665581² = 186846912135122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9665587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26520 + ... + 26881.

It is an arithmetic number, because the mean of its divisors is an integer number (2429791).

Almost surely, 2^9665581 is an apocalyptic number.

It is an amenable number.

9665581 is a deficient number, since it is larger than the sum of its proper divisors (53583).

9665581 is a wasteful number, since it uses less digits than its factorization.

9665581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53582.

The product of its digits is 64800, while the sum is 40.

The square root of 9665581 is about 3108.9517526009. The cubic root of 9665581 is about 213.0145757694.

The spelling of 9665581 in words is "nine million, six hundred sixty-five thousand, five hundred eighty-one".