9821965808265 has 128 divisors (see below), whose sum is σ = 17591786634240. Its totient is φ = 4648468070400.

The previous prime is 9821965808231. The next prime is 9821965808269. The reversal of 9821965808265 is 5628085691289.

9821965808265 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9821965808265 - 2²⁰ = 9821964759689 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 9821965808265.

It is not an unprimeable number, because it can be changed into a prime (9821965808269) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 208462060 + ... + 208509170.

It is an arithmetic number, because the mean of its divisors is an integer number (137435833080).

Almost surely, 2^{9821965808265} is an apocalyptic number.

It is an amenable number.

9821965808265 is a deficient number, since it is larger than the sum of its proper divisors (7769820825975).

9821965808265 is a wasteful number, since it uses less digits than its factorization.

9821965808265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47555.

The product of its (nonzero) digits is 149299200, while the sum is 69.

The spelling of 9821965808265 in words is "nine trillion, eight hundred twenty-one billion, nine hundred sixty-five million, eight hundred eight thousand, two hundred sixty-five".