9665052721 has 9 divisors (see below), whose sum is σ = 10268804011. Its totient is φ = 9094947232.

The previous prime is 9665052703. The next prime is 9665052739. The reversal of 9665052721 is 1272505669.

The square root of 9665052721 is 98311.

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

It is an interprime number because it is at equal distance from previous prime (9665052703) and next prime (9665052739).

It can be written as a sum of positive squares in only one way, i.e., 7524695025 + 2140357696 = 86745^2 + 46264^2 .

It is not a de Polignac number, because 9665052721 - 2¹¹ = 9665050673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9665052701) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1668396 + ... + 1674178.

Almost surely, 2^9665052721 is an apocalyptic number.

9665052721 is the 98311-st square number.

9665052721 is the 49156-th centered octagonal number.

It is an amenable number.

9665052721 is a deficient number, since it is larger than the sum of its proper divisors (603751290).

9665052721 is an frugal number, since it uses more digits than its factorization.

9665052721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11600 (or 5800 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 43.

The cubic root of 9665052721 is about 2130.1069487910.

The spelling of 9665052721 in words is "nine billion, six hundred sixty-five million, fifty-two thousand, seven hundred twenty-one".