65566016321 has 4 divisors (see below), whose sum is σ = 70609556052. Its totient is φ = 60522476592.

The previous prime is 65566016293. The next prime is 65566016323. The reversal of 65566016321 is 12361066556.

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 40526118721 + 25039897600 = 201311^2 + 158240^2 .

It is a cyclic number.

It is not a de Polignac number, because 65566016321 - 2¹⁴ = 65565999937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65566016323) 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, 2521769846 + ... + 2521769871.

It is an arithmetic number, because the mean of its divisors is an integer number (17652389013).

Almost surely, 2^65566016321 is an apocalyptic number.

It is an amenable number.

65566016321 is a deficient number, since it is larger than the sum of its proper divisors (5043539731).

65566016321 is a wasteful number, since it uses less digits than its factorization.

65566016321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5043539730.

The product of its (nonzero) digits is 194400, while the sum is 41.

The spelling of 65566016321 in words is "sixty-five billion, five hundred sixty-six million, sixteen thousand, three hundred twenty-one".