9665881 has 3 divisors (see below), whose sum is σ = 9668991. Its totient is φ = 9662772.

The previous prime is 9665863. The next prime is 9665891. The reversal of 9665881 is 1885669.

The square root of 9665881 is 3109.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1885669 = 233 ⋅8093.

It can be written as a sum of positive squares in only one way, i.e., 1713481 + 7952400 = 1309^2 + 2820^2 .

It is not a de Polignac number, because 9665881 - 2¹⁹ = 9141593 is a prime.

It is a super-2 number, since 2×9665881² = 186858511012322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9665891) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1555 + ... + 4663.

It is an arithmetic number, because the mean of its divisors is an integer number (3222997).

Almost surely, 2^9665881 is an apocalyptic number.

9665881 is the 3109-th square number.

9665881 is the 1555-th centered octagonal number.

It is an amenable number.

9665881 is a deficient number, since it is larger than the sum of its proper divisors (3110).

9665881 is an frugal number, since it uses more digits than its factorization.

9665881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6218 (or 3109 counting only the distinct ones).

The product of its digits is 103680, while the sum is 43.

The cubic root of 9665881 is about 213.0167795931.

The spelling of 9665881 in words is "nine million, six hundred sixty-five thousand, eight hundred eighty-one".